MAL_SCAR-1
Windows 2000, XP, Server 2003
Threat Type: Trojan
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
This Trojan executes commands from a remote malicious user, effectively compromising the affected system.
TECHNICAL DETAILS
Random TCP ports
Varies
PE
Yes
29 Apr 2010
Connects to websites to send and receive information
Installation
This Trojan drops the following copies of itself into the affected system:
- %System%\{random file name}.EXE
(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.)
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\
Services\{service name}
ImagePath = %System%\{malware file name}.EXE
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{service name}
Start = 2
Backdoor Routine
This Trojan executes the following commands from a remote malicious user:
- Downloads and executes files from certain websites
- Starts and stops certain IIS services
Other Details
This Trojan does the following:
- Connects to any of the following URLs via random TCP ports to send and receive information:
- http://xhsb.{BLOCKED}22.org
- http://wanmei8013.{BLOCKED}22.org
- http://avzhan1.{BLOCKED}22.org
- {BLOCKED}.3322.org
- Sends data that contains the following information:
- Computer Name
- Locale Info
- OS Version
- Product Name
- CPU Speed
- Memory Size
- Manifests similar behavior and characteristics as the following malware:
SOLUTION
8.900
7.137.80
29 Apr 2010
4/29/2010 12:00:00 AM
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
Identify and terminate files detected as MAL_SCAR-1
- If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
Step 3
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
- {service name}
Step 4
Scan your computer with your Trend Micro product to delete files detected as MAL_SCAR-1. 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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