TROJ_FAKEAV.HLR

October 09, 2012
 Modified by: Christopher Daniel So
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware

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.

However, as of this writing, the said sites are inaccessible. It deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size:

475,136 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

27 May 2012

Payload:

Connects to URLs/IPs

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:

  • {All Users' profile}\Application Data\529C50D800009E46005FBEC6D151FC4E\529C50D800009E46005FBEC6D151FC4E.EXE

It drops the following non-malicious file:

  • {All Users' profile}\Application Data\529C50D800009E46005FBEC6D151FC4E\529C50D800009E46005FBEC6D151FC4E

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • 529C50D800009E46005FBEC6D151FC4E

It terminates the execution of the copy it initially executed and executes the copy it drops instead.

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
529C50D800009E46005FBEC6D151FC4E = "{All Users' profile}\Application Data\529C50D800009E46005FBEC6D151FC4E\529C50D800009E46005FBEC6D151FC4E.EXE"

Other Details

This Trojan attempts to access the following websites to download files, which are possibly malicious:

  • http://{BLOCKED}.{BLOCKED}.140.246/api/urls/?ts=79680aa0&affid=14400
  • http://{BLOCKED}.{BLOCKED}.140.246/api/stats/install/?ts=79680aa0&affid=14400&ver=3040003&group=sf

However, as of this writing, the said sites are inaccessible.

It deletes the initially executed copy of itself

  SOLUTION

Minimum Scan Engine:

9.200

VSAPI OPR PATTERN File:

9.145.00

VSAPI OPR PATTERN Date:

27 May 2012

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 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\CurrentVersion\RunOnce
    • 529C50D800009E46005FBEC6D151FC4E = "{All Users' profile}\Application Data\529C50D800009E46005FBEC6D151FC4E\529C50D800009E46005FBEC6D151FC4E.EXE"

Step 4

Search and delete this file

[ 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.
  • {All Users' profile}\Application Data\529C50D800009E46005FBEC6D151FC4E\529C50D800009E46005FBEC6D151FC4E

Step 5

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