TROJ_FAKEAV.RKG

October 09, 2012
 Analysis by: Christopher Daniel So
 ALIASES:

Trojan:Win32/FakeSysdef (Microsoft), Trojan.FakeAV (Symantec), FakeAlert-SysDef.b (McAfee)

 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 arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It modifies the Internet Explorer Zone Settings.

It deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size:

348,672 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

18 Oct 2011

Arrival Details

This Trojan 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 Trojan drops the following copies of itself into the affected system:

  • %System Root%\Documents and Settings\All Users\Application Data\{random file name}.exe

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

It drops the following files:

  • %Desktop%\System Restore.lnk
  • %Start Menu%\Programs\System Restore\System Restore.lnk
  • %Start Menu%\Programs\System Restore\Uninstall System Restore.lnk
  • %System Root%\Documents and Settings\All Users\Application Data\{random file name}
  • %System Root%\Documents and Settings\All Users\Application Data\~{random file name}
  • %System Root%\Documents and Settings\All Users\Application Data\~{random file name}r
  • %User Profile%\Application Data\Microsoft\Internet Explorer\Quick Launch\System Restore.lnk

(Note: %Desktop% is the current user's desktop, which is usually C:\Windows\Profiles\{user name}\Desktop on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Desktop on Windows NT, and C:\Documents and Settings\{User Name}\Desktop on Windows 2000, XP, and Server 2003.. %Start Menu% is the current user's Start Menu folder, which is usually C:\Windows\Profiles\{user name}\Start Menu on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu on Windows NT and C:\Windows\Start Menu or C:\Documents and Settings\{User name}\Start Menu on Windows 2000, XP, and Server 2003.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)

Web Browser Home Page and Search Page Modification

This Trojan modifies the Internet Explorer Zone Settings.

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}20186.com/britix/a
  • http://{BLOCKED}520186.com/britix/ar

It deletes the initially executed copy of itself

  SOLUTION

Minimum Scan Engine:

9.200

FIRST VSAPI PATTERN FILE:

8.506.05

FIRST VSAPI PATTERN DATE:

18 Oct 2011

VSAPI OPR PATTERN File:

8.507.00

VSAPI OPR PATTERN Date:

19 Oct 2011

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

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

Step 3

Search and delete these files

[ Learn More ]
There may be some component files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • %Desktop%\System Restore.lnk
  • %Start Menu%\Programs\System Restore\System Restore.lnk
  • %Start Menu%\Programs\System Restore\Uninstall System Restore.lnk
  • %System Root%\Documents and Settings\All Users\Application Data\{random file name}
  • %System Root%\Documents and Settings\All Users\Application Data\~{random file name}
  • %System Root%\Documents and Settings\All Users\Application Data\~{random file name}r
  • %User Profile%\Application Data\Microsoft\Internet Explorer\Quick Launch\System Restore.lnk

Step 4

Reset Internet security settings

[ Learn More ]

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_FAKEAV.RKG. 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.


Did this description help? Tell us how we did.