WORM_FAKER.AH

 Modified by: RonJay Kristoffer Caragay

 ALIASES:

FakeRecycled (McAfee); Worm:Win32/Fakerecy.A (Microsoft); W32.Fakerecy (Symantec), Win32:VB-EAA [Trj] (Avast)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003, Windows 7

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

  • 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.

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

  TECHNICAL DETAILS

File Size:

20,480 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

17 Jan 2013

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.

Installation

This worm creates the following folders:

  • {drive letter}:\Recycled
  • {driver letter}:\Recycled\Recycled

Autostart Technique

This worm drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:

  • %User Startup%\ctfmon.exe

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Documents and Settings\{user}\Start Menu\Programs\Startup on Windows 2000 and XP, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)

Propagation

This worm drops the following copy of itself in all physical and removable drives:

  • {drive letter}:\Recycled\Recycled\ctfmon.exe

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

The said .INF file contains the following strings:

[autorun]
shellexecute=Recycled\ctfmon.exe
shell\Open(&0)\command=Recycled\ctfmon.exe
shell=Open(&0)

Dropping Routine

This worm drops the following files:

  • {drive letter}:\Recycled\INFO2
  • {drive letter}:\Recycled\desktop.ini

  SOLUTION

Minimum Scan Engine:

9.700

FIRST VSAPI PATTERN FILE:

10.488.03

FIRST VSAPI PATTERN DATE:

22 Dec 2013

VSAPI OPR PATTERN File:

10.489.00

VSAPI OPR PATTERN Date:

22 Dec 2013

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

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Search and delete AUTORUN.INF files created by WORM_FAKER.AH that contain these strings

[ Learn More ]
  • [autorun]
  • shellexecute=Recycled\ctfmon.exe
  • shell\Open(&0)\command=Recycled\ctfmon.exe
  • shell=Open(&0)

Step 4

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • {drive letter}:\Recycled

Step 5

Scan your computer with your Trend Micro product to delete files detected as WORM_FAKER.AH. 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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