TROJ_SIREFEF.AE

January 21, 2013
 Analysis by: Lord Alfred Remorin
 ALIASES:

TrojanDropper:Win32/Sirefef.B (Microsoft), BackDoor-FCS (McAfee), Trojan.Zeroaccess (Symantec)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Trojan may be dropped by other malware.

  TECHNICAL DETAILS

File Size:

60416 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

22 Jan 2012

Arrival Details

This Trojan may be dropped by other malware.

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Winlogon
Shell = "%Application Data%\c397c700\X"

  SOLUTION

Minimum Scan Engine:

9.200

FIRST VSAPI PATTERN FILE:

8.724.07

FIRST VSAPI PATTERN DATE:

22 Jan 2012

VSAPI OPR PATTERN File:

8.725.00

VSAPI OPR PATTERN Date:

22 Jan 2012

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

Restart in Safe Mode

[ Learn More ]

Step 3

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 NT\CurrentVersion\Winlogon
    • Shell = "%Application Data%\c397c700\X"

Step 4

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