TROJ_DISCPER.A
Trojan:Win32/Discper.A (Microsoft); Trojan.Coinbitminer (Symantec); Trojan.Win32.Reconyc.cdho (Kaspersky); Mal/Generic-L (Sophos); BehavesLike.Win32.Malware.eah (mx-v) (Sunbelt); Trojan horse SHeur4.CAGK (AVG)
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
Threat Type: Trojan
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It deletes itself after execution.
TECHNICAL DETAILS
Arrival Details
This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
Installation
This Trojan drops the following copies of itself into the affected system:
- %User Profile%\RDPServicev19\termsvc.exe
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)
It creates the following folders:
- %User Profile%\Application Data\RDPServicev19
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Microsoft Windows RDP Service v19 = "%User Profile%\RDPServicev19\termsvc.exe"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
Microsoft Windows RDP Service v19 = "%User Profile%\RDPServicev19\termsvc.exe"
Other System Modifications
This Trojan deletes the following files:
- %User Temp%\libeay32.dll
- %User Temp%\libgcc_s_seh-1.dll
- %User Temp%\libstdc++-6.dll
- %User Profile%\Waxter\exceptionfilter.exe
- %User Profile%\DrkWaxter\exceptionfilter.exe
- %User Profile%\GoodDrkWaxter\exceptionfilter.exe
- %User Profile%\VeryGoodDrkWaxter\exceptionfilter.exe
- %User Profile%\Mokako\exceptionfilter.exe
- %User Profile%\NewMokako\exceptionfilter.exe
- %User Profile%\AESMokako\exceptionfilter.exe
- %User Profile%\NewAES\exceptionfilter.exe
- %User Profile%\EventLogs\eventlogservice.exe
- %User Profile%\TerminalServices\termsvc.exe
- \Microsoft\Windows NT\MSSyn\ssyncer.exe
- \Microsoft\Windows NT\MSSyn\svchost.exe
- %User Profile%\TermServices\termsvc.exe
- %User Profile%\TermServ\termsvc.exe
- %User Profile%\MsWinTermSvc\termsvc.exe
- %User Profile%\MsWinTermSvc_v2\termsvc.exe
- %User Profile%\MsWinTermSvc_v3\termsvc.exe
- %User Profile%\MsWinTermSvc_v4\termsvc.exe
- %User Profile%\MsWinTermSvc_v5\termsvc.exe
- %User Profile%\MsWinTermSvc_v6\termsvc.exe
- %User Profile%\RDPService\termsvc.exe
- %User Profile%\RDPServicev2\termsvc.exe
- %User Profile%\RDPServicev3\termsvc.exe
- %User Profile%\RDPServicev4\termsvc.exe
- %User Profile%\RDPServicev5\termsvc.exe
- %User Profile%\RDPServicev6\termsvc.exe
- %User Profile%\RDPServicev8\termsvc.exe
- %User Profile%\RDPServicev9\termsvc.exe
- %User Profile%\RDPServicev10\termsvc.exe
- %User Profile%\RDPServicev11\termsvc.exe
- %User Profile%\RDPServicev12\termsvc.exe
- %User Profile%\RDPServicev13\termsvc.exe
- %User Profile%\RDPServicev14\termsvc.exe
- %User Profile%\RDPServicev15\termsvc.exe
- %User Profile%\RDPServicev16\termsvc.exe
- %User Profile%\RDPServicev17\termsvc.exe
- %User Profile%\RDPServicev18\termsvc.exe
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)
Dropping Routine
This Trojan drops the following files:
- %User Temp%\svchost.exe
- %User Temp%\libcurl.dll
- %User Temp%\msvcr100.dll
- %User Temp%\pthreadVC2.dll
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)
Other Details
This Trojan deletes itself after execution.
This report is generated via an automated analysis system.
SOLUTION
Step 1
Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.
Step 2
Restart in Safe Mode
Step 3
Delete this registry value
Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- Microsoft Windows RDP Service v19 = "%User Profile%\RDPServicev19\termsvc.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce
- Microsoft Windows RDP Service v19 = "%User Profile%\RDPServicev19\termsvc.exe"
Step 4
Search and delete these components
- %User Temp%\svchost.exe
- %User Temp%\libcurl.dll
- %User Temp%\msvcr100.dll
- %User Temp%\pthreadVC2.dll
Step 5
Search and delete this folder
- %User Profile%\Application Data\RDPServicev19
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_DISCPER.A. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.
Step 7
Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.
- %User Temp%\libeay32.dll
- %User Temp%\libgcc_s_seh-1.dll
- %User Temp%\libstdc++-6.dll
- %User Profile%\Waxter\exceptionfilter.exe
- %User Profile%\DrkWaxter\exceptionfilter.exe
- %User Profile%\GoodDrkWaxter\exceptionfilter.exe
- %User Profile%\VeryGoodDrkWaxter\exceptionfilter.exe
- %User Profile%\Mokako\exceptionfilter.exe
- %User Profile%\NewMokako\exceptionfilter.exe
- %User Profile%\AESMokako\exceptionfilter.exe
- %User Profile%\NewAES\exceptionfilter.exe
- %User Profile%\EventLogs\eventlogservice.exe
- %User Profile%\TerminalServices\termsvc.exe
- \Microsoft\Windows NT\MSSyn\ssyncer.exe
- \Microsoft\Windows NT\MSSyn\svchost.exe
- %User Profile%\TermServices\termsvc.exe
- %User Profile%\TermServ\termsvc.exe
- %User Profile%\MsWinTermSvc\termsvc.exe
- %User Profile%\MsWinTermSvc_v2\termsvc.exe
- %User Profile%\MsWinTermSvc_v3\termsvc.exe
- %User Profile%\MsWinTermSvc_v4\termsvc.exe
- %User Profile%\MsWinTermSvc_v5\termsvc.exe
- %User Profile%\MsWinTermSvc_v6\termsvc.exe
- %User Profile%\RDPService\termsvc.exe
- %User Profile%\RDPServicev2\termsvc.exe
- %User Profile%\RDPServicev3\termsvc.exe
- %User Profile%\RDPServicev4\termsvc.exe
- %User Profile%\RDPServicev5\termsvc.exe
- %User Profile%\RDPServicev6\termsvc.exe
- %User Profile%\RDPServicev8\termsvc.exe
- %User Profile%\RDPServicev9\termsvc.exe
- %User Profile%\RDPServicev10\termsvc.exe
- %User Profile%\RDPServicev11\termsvc.exe
- %User Profile%\RDPServicev12\termsvc.exe
- %User Profile%\RDPServicev13\termsvc.exe
- %User Profile%\RDPServicev14\termsvc.exe
- %User Profile%\RDPServicev15\termsvc.exe
- %User Profile%\RDPServicev16\termsvc.exe
- %User Profile%\RDPServicev17\termsvc.exe
- %User Profile%\RDPServicev18\termsvc.exe
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