TROJ_ANTIAV.TOMS
Backdoor:Win32/PcClient.AA, Virus:Win32/Parite.B (Microsoft); Generic Dropper.pa (McAfee); Backdoor.Win32.PcClient (Sunbelt); Trojan horse Generic14.PRX (AVG)
Windows 2000, Windows XP, Windows Server 2003
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.
TECHNICAL DETAILS
413,698 bytes
EXE
No
17 Jun 2013
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.
Other System Modifications
This Trojan modifies the following registry entries:
HKEY_CURRENT_USER\SessionInformation
ProgramCount = "1"
(Note: The default value data of the said registry entry is 2.)
HKEY_CURRENT_USER\SessionInformation
ProgramCount = "0"
(Note: The default value data of the said registry entry is 2.)
It deletes the following registry keys:
HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Active Setup\Installed Components
Dropping Routine
This Trojan drops the following files:
- %User Temp%\k.exe
- %System Root%\ºÚÊÖÈÐ×îÐÂÃâɱÍøÂí.exe
- %User Temp%\xra5.tmp
- %Windows%\linkinfo.dll
- %System%\drivers\IsDrv122.sys
(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.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %Windows% is the Windows folder, which is usually C:\Windows.. %System% is the Windows system folder, which is usually C:\Windows\System32.)
This report is generated via an automated analysis system.
SOLUTION
9.300
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
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.
- In HKEY_CURRENT_USER\SessionInformation
- From: ProgramCount = "1"
To: ProgramCount = ""2""
- From: ProgramCount = "1"
- In HKEY_CURRENT_USER\SessionInformation
- From: ProgramCount = "0"
To: ProgramCount = ""2""
- From: ProgramCount = "0"
Step 3
Search and delete these components
- %User Temp%\k.exe
- %System Root%\ºÚÊÖÈÐ×îÐÂÃâɱÍøÂí.exe
- %User Temp%\xra5.tmp
- %Windows%\linkinfo.dll
- %System%\drivers\IsDrv122.sys
Step 4
Scan your computer with your Trend Micro product to delete files detected as TROJ_ANTIAV.TOMS. 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 5
Restore these deleted registry keys/values from backup
*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.
- In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Active Setup
- Installed Components
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