TROJ_SCAR.MQ
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Trojan
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
This Trojan deletes itself after execution.
TECHNICAL DETAILS
48,640 bytes
EXE
No
09 Mar 2011
Drops files
Installation
This Trojan drops the following copies of itself into the affected system:
- %Program Files%\{random filename}.exe
(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- WMMNetworkExo
It terminates the execution of the copy it initially executed and executes the copy it drops instead.
Autostart Technique
This Trojan registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_WMMNETWORKEXO\
0000
Service = WMMNetworkExo
Other System Modifications
This Trojan adds the following registry keys:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Enum\Root\LEGACY_WMMNETWORKEXO
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WMMNetworkExo
Backdoor Routine
This Trojan connects to the following URL(s) to send and receive commands from a remote malicious user:
- {BLOCKED}nwan.3322.org
Other Details
This Trojan deletes itself after execution.
SOLUTION
8.900
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
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\Enum\Root\
- LEGACY_WMMNETWORKEXO
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\
- WMMNetworkExo
Step 3
Scan your computer with your Trend Micro product to delete files detected as TROJ_SCAR.MQ. 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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