MVISION Insights: EtterSilent Maldoc Builder
Technical Articles ID:
KB94910
Last Modified: 9/22/2021
Last Modified: 9/22/2021
Environment
IMPORTANT: This Knowledge Base article discusses a specific threat that is being automatically tracked by MVISION Insights technology. The content is intended for use by MVISION Insights users, but is provided for general knowledge to all customers. Contact us for more information about MVISION Insights.
Summary
A malicious document builder (maldoc), known as "EtterSilent," is being sold on the underground market. The seller is offering one weaponized maldoc which exploits a flaw in Microsoft Office classified under CVE-2017-8570 and one document that uses a malicious macro. Victims are presented with a fake document mimicking a template from the popular DocuSign electronic signature software. Excel 4.0 macros stored in a hidden sheet, regsvr32 or rundll32 are used for execution and to download a payload from an actor-controlled website. Various backdoors and remote access trojans including Gozi, Qbot, Trickbot, IcedID, and Bazar are then dropped onto the infected system.
The McAfee Enterprise ATR Team gathers and analyzes information from multiple open and closed sources before disseminating intelligence reports.
This campaign was researched by Intel 471 and shared publicly.
How to use this article:
- If a Threat Hunting table has been created, use the rules contained to search for malware related to this campaign.
- Review the product detection table and confirm that your environment is at least on the specified content version.
To download the latest content versions, go to the Security Updates page. - Scroll down and review the "Product Countermeasures" section of this article. Consider implementing them if they are not already in place.
- Review
KB91836 - Countermeasures for entry vector threats . - Review KB87843 - Dynamic Application Containment rules and best practices.
- Review KB82925 - Identify what rule corresponds to an Adaptive Threat Protection and Threat Intelligence Exchange event.
This Knowledge Base article discusses a specific threat that is being tracked. The list of IOCs will change over time; check MVISION Insights for the latest IOCs.
Campaign IOC
| Type | Value |
| SHA256 | D5B05A81F377C33A2FBA292002D0474B68483225AA09C97A00336FC368383D6A |
| SHA256 | 3A5D67BDC42B7A9EBD1137E49A34D82C0EE99343AE32F3367137DB19131C2CF4 |
| SHA256 | 5F8E3B19CD4D25AC396CF64F6F448D88E301CF899142BDB03A28CEC42EB71389 |
| SHA256 | 50FD4B2E51908A55F2C891FB3FFDE2C3661E4324C1887E65FABFB1A93A41EFB2 |
| SHA256 | 9B1C03B0CCA23A94F2D6988C66EB0D246EC2648623765E83DBF20548AC874837 |
| SHA256 | AA40F9DD1212993F79CC23111DE3A8DD5E529DD1A8CA5DCEAA30FBA53F6F96B4 |
| SHA256 | 6A984D3AAFFEEEC32F3803489C71BFD907E2FB74DBC8EEB931C084F11293E1CC |
| SHA256 | 267A54F074B688D591D5CFB7831F1ADB443EC1441076775CB158BED0D385F712 |
| SHA256 | 9118198AFCA6E2479FDBCCA55A08A4408570D2186A7DD8F261F1821178DEB595 |
| SHA256 | 8E51CCC6C8D14F0365D2D597C8AAF6015238839C0DAB90E419107782BF460414 |
| SHA256 | 2BAF563DA8DB9E2ED765FA7697025D277D06EE53424F6513671F2F6B7441387B |
| SHA256 | B7CE29FFBDF00771B539B28CE01D57CD5805CA3A6CA2EB1B694EED4466912286 |
| SHA256 | 16A0C2F741A14C423B7ABE293E26F711FDB984FC52064982D874BF310C520B12 |
| SHA256 | 24753D9F0D691B6D582DA3E301B98F75ABBDB5382BB871EE00713C5029C56D44 |
| SHA256 | 2A3316B69EC787CA13A3E35697BCFC4A5E37A9A3080434C56FDF17E0593E0A12 |
| URL | http://itelsys.ma/prod/education.php |
| URL | http://188.127.254.114/44270.7082388889.dat |
| URL | http://kfzhm28pwzrlk02bmjy.com/mrch.gif |
| URL | http://pokojewewladyslawowie.pl/orlpzhiy/44270.5684626157.dat |
| URL | http://costacars.es/ico/ortodox.php |
| URL | http://mineiro.ch/casrtnoar/count.php |
| URL | http://musclemodz.com/asrt3.png |
| URL | http://holmesservices.mobiledevsite.co/ds/2803.gif |
Minimum Content Versions:
| Content Type | Version |
| V2 DAT (VirusScan Enterprise) | 9963 |
| V3 DAT (Endpoint Security) | 4498 |
Detection Summary
| IOC | Scanner | Detection |
| D5B05A81F377C33A2FBA292002D0474B68483225AA09C97A00336FC368383D6A | AVEngine V2 | RDN/PWS-Banker |
| AVEngine V3 | RDN/PWS-Banker | |
| JTI (ATP Rules) | JTI/Suspect.196612!0919ea140924 | |
| RP Static | Real Protect-PEAGG!0919EA140924 | |
| RP Dynamic | - |
| IOC | Scanner | Detection |
| 3A5D67BDC42B7A9EBD1137E49A34D82C0EE99343AE32F3367137DB19131C2CF4 | AVEngine V2 | Downloader-FCED!0D040A8311F7 |
| AVEngine V3 | Downloader-FCED!0D040A8311F7 | |
| JTI (ATP Rules) | JTI/Suspect.196612!5089fcd4da2b | |
| RP Static | - | |
| RP Dynamic | - |
| IOC | Scanner | Detection |
| 5F8E3B19CD4D25AC396CF64F6F448D88E301CF899142BDB03A28CEC42EB71389 | AVEngine V2 | Downloader-FCED!1308478B9DFA |
| AVEngine V3 | Downloader-FCED!1308478B9DFA | |
| JTI (ATP Rules) | - | |
| RP Static | - | |
| RP Dynamic | - |
| IOC | Scanner | Detection |
| 50FD4B2E51908A55F2C891FB3FFDE2C3661E4324C1887E65FABFB1A93A41EFB2 | AVEngine V2 | W97M/Downloader.cym |
| AVEngine V3 | W97M/Downloader.cym | |
| JTI (ATP Rules) | - | |
| RP Static | - | |
| RP Dynamic | - |
| IOC | Scanner | Detection |
| 9B1C03B0CCA23A94F2D6988C66EB0D246EC2648623765E83DBF20548AC874837 | AVEngine V2 | Downloader-FCED!2B0E8B9CEE36 |
| AVEngine V3 | Downloader-FCED!2B0E8B9CEE36 | |
| JTI (ATP Rules) | - | |
| RP Static | - | |
| RP Dynamic | - |
| IOC | Scanner | Detection |
| AA40F9DD1212993F79CC23111DE3A8DD5E529DD1A8CA5DCEAA30FBA53F6F96B4 | AVEngine V2 | Emotet-FRU!35994B0F330D |
| AVEngine V3 | Emotet-FRU!35994B0F330D | |
| JTI (ATP Rules) | JTI/Suspect.196612!35994b0f330d | |
| RP Static | - | |
| RP Dynamic | - |
| IOC | Scanner | Detection |
| 6A984D3AAFFEEEC32F3803489C71BFD907E2FB74DBC8EEB931C084F11293E1CC | AVEngine V2 | W32/PinkSbot-HR!5089FCD4DA2B |
| AVEngine V3 | W32/PinkSbot-HR!5089FCD4DA2B | |
| JTI (ATP Rules) | JTI/Suspect.196612!5089fcd4da2b | |
| RP Static | - | |
| RP Dynamic | - |
| IOC | Scanner | Detection |
| 267A54F074B688D591D5CFB7831F1ADB443EC1441076775CB158BED0D385F712 | AVEngine V2 | Downloader-FCED!552B22675B5D |
| AVEngine V3 | Downloader-FCED!552B22675B5D | |
| JTI (ATP Rules) | - | |
| RP Static | - | |
| RP Dynamic | - |
| IOC | Scanner | Detection |
| 9118198AFCA6E2479FDBCCA55A08A4408570D2186A7DD8F261F1821178DEB595 | AVEngine V2 | Emotet-FRU!5B94175E4686 |
| AVEngine V3 | Emotet-FRU!5B94175E4686 | |
| JTI (ATP Rules) | JTI/Suspect.196612!5b94175e4686 | |
| RP Static | - | |
| RP Dynamic | - |
| IOC | Scanner | Detection |
| 8E51CCC6C8D14F0365D2D597C8AAF6015238839C0DAB90E419107782BF460414 | AVEngine V2 | RDN/IcedID |
| AVEngine V3 | RDN/IcedID | |
| JTI (ATP Rules) | JTI/Suspect.196612!5bf34d9fe5da | |
| RP Static | - | |
| RP Dynamic | - |
| IOC | Scanner | Detection |
| 2BAF563DA8DB9E2ED765FA7697025D277D06EE53424F6513671F2F6B7441387B | AVEngine V2 | Downloader-FCED!632C4D92E87E |
| AVEngine V3 | Downloader-FCED!632C4D92E87E | |
| JTI (ATP Rules) | - | |
| RP Static | - | |
| RP Dynamic | - |
| IOC | Scanner | Detection |
| B7CE29FFBDF00771B539B28CE01D57CD5805CA3A6CA2EB1B694EED4466912286 | AVEngine V2 | MLFNG |
| AVEngine V3 | MLFNG | |
| JTI (ATP Rules) | JTI/Suspect.196612!656cf5de4c90 | |
| RP Static | - | |
| RP Dynamic | - |
| IOC | Scanner | Detection |
| 16A0C2F741A14C423B7ABE293E26F711FDB984FC52064982D874BF310C520B12 | AVEngine V2 | Downloader-FCDT!66E5E724F99A |
| AVEngine V3 | Downloader-FCDT!66E5E724F99A | |
| JTI (ATP Rules) | - | |
| RP Static | - | |
| RP Dynamic | - |
| IOC | Scanner | Detection |
| 24753D9F0D691B6D582DA3E301B98F75ABBDB5382BB871EE00713C5029C56D44 | AVEngine V2 | Qakbot.e |
| AVEngine V3 | Qakbot.e | |
| JTI (ATP Rules) | JTI/Suspect.196612!97e6abcad214 | |
| RP Static | - | |
| RP Dynamic | - |
| IOC | Scanner | Detection |
| 2A3316B69EC787CA13A3E35697BCFC4A5E37A9A3080434C56FDF17E0593E0A12 | AVEngine V2 | X97M/Downloader.ib |
| AVEngine V3 | X97M/Downloader.ib | |
| JTI (ATP Rules) | - | |
| RP Static | - | |
| RP Dynamic | - |
Minimum set of Manual Rules to improve protection to block this campaign
IMPORTANT: Always follow best practices when you enable new rules and signatures.
When you implement new rules or signatures, always set them to Report mode first and check the alerts generated. Resolve any issues that arise and then set the rules to Block. This step mitigates against triggering false positives and allows you to refine your configuration.
For more information, see KB87843 - List of and best practices for Endpoint Security Dynamic Application Containment rules.
Endpoint Security - Advanced Threat Protection:
Rule ID: 4 Use GTI file reputation to identify trusted or malicious files
Endpoint Security - Exploit Prevention:
Rule ID: 6135 Unmanaged Powershell Detected
Endpoint Security - Access Protection Custom Rules:
Rule: 1
Executables (Include):
excel.exe
Subrules:
Subrule Type: Files
Operations:
execute
Targets (Include):
rundll32.exe
excel.exe
Subrules:
Subrule Type: Files
Operations:
execute
Targets (Include):
rundll32.exe
Rule: 2
Executables (Include):
excel.exe
Subrules:
Subrule Type: Files
Operations:
create
Targets (Include):
?:\users\*\*.det
excel.exe
Subrules:
Subrule Type: Files
Operations:
create
Targets (Include):
?:\users\*\*.det
Rule: 3
Executables (Include):
excel.exe
Subrules:
Subrule Type: Files
Operations:
create
Targets (Include):
?:\users\*\*.dati1
excel.exe
Subrules:
Subrule Type: Files
Operations:
create
Targets (Include):
?:\users\*\*.dati1
Rule: 4
Executables (Include):
excel.exe
Subrules:
Subrule Type: Files
Operations:
create
Targets (Include):
?:\users\*\*.dsk2
excel.exe
Subrules:
Subrule Type: Files
Operations:
create
Targets (Include):
?:\users\*\*.dsk2
Rule: 5
Executables (Include):
excel.exe
Subrules:
Subrule Type: Files
Operations:
create
Targets (Include):
?:\users\*\*.dsk
excel.exe
Subrules:
Subrule Type: Files
Operations:
create
Targets (Include):
?:\users\*\*.dsk
VirusScan Enterprise - Access Protection Custom Rules:
Rule: 1
Rule Type: File
Process to include: excel.exe
File or folder name to block: *\users\*\*.det
File actions to prevent: Create
Process to include: excel.exe
File or folder name to block: *\users\*\*.det
File actions to prevent: Create
Rule: 2
Rule Type: File
Process to include: excel.exe
File or folder name to block: rundll32.exe
File actions to prevent: Terminate
Process to include: excel.exe
File or folder name to block: rundll32.exe
File actions to prevent: Terminate
Rule: 3
Rule Type: File
Process to include: excel.exe
File or folder name to block: *\users\*\*.dati1
File actions to prevent: Create
Process to include: excel.exe
File or folder name to block: *\users\*\*.dati1
File actions to prevent: Create
Rule: 4
Rule Type: File
Process to include: excel.exe
File or folder name to block: *\users\*\*.dsk2
File actions to prevent: Create
Process to include: excel.exe
File or folder name to block: *\users\*\*.dsk2
File actions to prevent: Create
Rule: 5
Rule Type: File
Process to include: excel.exe
File or folder name to block: *\users\*\*.dsk
File actions to prevent: Create
Process to include: excel.exe
File or folder name to block: *\users\*\*.dsk
File actions to prevent: Create
Aggressive set of Manual Rules to improve protection to block this campaign
IMPORTANT: Always follow best practices when you enable new rules and signatures.
When you implement new rules or signatures, always set them to Report mode first and check the alerts generated. Resolve any issues that arise and then set the rules to Block. This step mitigates against triggering false positives and allows you to refine your configuration.
For more information, see KB87843 - List of and best practices for Endpoint Security Dynamic Application Containment rules.
Virusscan Enterprise - Access Protection Rules:
Prevent creation of new executable files in the Windows folder
Host Intrusion Prevention:
Rule ID: 1148 CMD Tool Access by a Network Aware Application
Rule ID: 6011 Generic Application Invocation Protection
Rule ID: 1020 Windows Agent Shielding - File Access
Rule ID: 2806 Attempt to create a hardlink to a file
