Analysis by: Michael Cabel
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

This worm may be dropped by other malware.

  TECHNICAL DETAILS

File Size: 72,704 bytes
File Type: DLL
Memory Resident: Yes
Initial Samples Received Date: 28 Mar 2009

Arrival Details

This worm may be dropped by other malware.

Autostart Technique

This worm 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}
Image Path = "%Windows%\System32\svchost.exe -k netsvcs""

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{Service Name}\ Parameters
ServiceDll = "{Malware path and file name}"

Other Details

This worm connects to the following URL(s) to get the affected system's IP address:

  • http://checkip.dyndns.org
  • http://{BLOCKED}p.co.uk
  • http://www.{BLOCKED}p.org

  SOLUTION

Minimum Scan Engine: 8.900
FIRST VSAPI PATTERN FILE: 5.926.19
FIRST VSAPI PATTERN DATE: 28 Mar 2009

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

Scan your computer with your Trend Micro product and note files detected as WORM_DOWNAD.AE

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Delete this registry key

[ Learn More ]

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 5

Delete this registry value

[ Learn More ]

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
    • {random characters} = "rundll32.exe {malware path and file name}, Parameter"

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_DOWNAD.AE. 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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