WORM_AGENT.CF
Backdoor:Win32/Joanap.A (Microsoft); Worm.Win32.Agent.age (Kaspersky)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This worm 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
208,896 bytes
EXE
No
28 Sep 2011
Arrival Details
This worm arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
Autostart Technique
This worm registers its dropped component as a system service to ensure its automatic execution at every system startup. It does this by creating the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SCardPrv
Type = "20"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SCardPrv
Start = "2"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SCardPrv
ErrorControl = "1"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SCardPrv
ImagePath = "%System Root%\system32\svchost.exe -k SCardPrv"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SCardPrv
DisplayName = "SmartCard Protector"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SCardPrv
ObjectName = "LocalSystem"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SCardPrv
Description = "Manages and controls access to a smart card inserted into a smart card reader attached to the computer and protect from others. "
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SCardPrv\Parameters
ServiceDll = "%SystemRoot%\system32\scardprv.dll"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Wmmvsvc
Type = "20"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Wmmvsvc
Start = "2"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Wmmvsvc
ErrorControl = "1"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Wmmvsvc
ImagePath = "%SystemRoot%\system32\svchost.exe -k Wmmvsvc"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Wmmvsvc
DisplayName = "Windows Media Management Driver Extensions"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Wmmvsvc
ObjectName = "LocalSystem"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Wmmvsvc
Description = "Provides Windows Media management information to and from drivers. "
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Wmmvsvc\Parameters
ServiceDll = "%SystemRoot%\system32\Wmmvsvc.dll"
It registers its dropped component as a system service to ensure its automatic execution at every system startup. It does this by creating the following registry keys:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SCardPrv
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Wmmvsvc
Other System Modifications
This worm adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\SvcHost
SCardPrv = "SCardPrv"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\SvcHost
Wmmvsvc = "Wmmvsvc"
Dropping Routine
This worm drops the following files:
- %System%\KB25879.dat
- %System%\mssscardprv.ax
- %System%\scardprv.dll
- %System%\Wmmvsvc.dll
(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)
SOLUTION
9.200
8.460.17
29 Sep 2011
8.461.00
29 Sep 2011
Step 1
For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SvcHost
- SCardPrv = "SCardPrv"
- SCardPrv = "SCardPrv"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SvcHost
- Wmmvsvc = "Wmmvsvc"
- Wmmvsvc = "Wmmvsvc"
Step 4
Delete this registry key
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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
- SCardPrv
- SCardPrv
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
- Wmmvsvc
- Wmmvsvc
Step 5
Search and delete these files
- %System%\KB25879.dat
- %System%\mssscardprv.ax
- %System%\scardprv.dll
- %System%\Wmmvsvc.dll
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_AGENT.CF. 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.
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