TROJ_FAKEAV.ECS

 Analysis by: Maydalene Edsel Salvador

 ALIASES:

FakeAlert-SpyPro.gen.h (NAI), Trojan.Generic.KD.11541 (Fsecure), W32/FakeAlert.FM.gen!Eldorado (AUTHENTIUM), Trojan W32/FakeAV.ABEL (Norman)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

 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 deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size:

899,600 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

14 May 2010

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 and executes them:

  • %Application Data%\{RANDOM_NUMBERS}\{RANDOM_NUMBERS}.exe

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

It drops the following files:

  • %Application Data%\{RANDOM_NUMBERS}\{RANDOM_NUMBERS}.bat

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

It creates the following folders:

  • %Application Data%\{RANDOM_NUMBERS}

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{RANDOM_NUMBERS} = %Application Data%\{RANDOM_NUMBERS}\{RANDOM_NUMBERS}.exe

It drops the following shortcut pointing to its copy in the User Startup folder to enable its automatic execution at every system startup:

  • %Desktop%Security Tool.lnk
  • %Start Menu%\Programs\Security Tool.lnk

(Note: %Desktop% is the current user's desktop, which is usually C:\Documents and Settings\{User Name}\Desktop on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\Desktop on Windows Vista and 7.. %Start Menu% is the current user's Start Menu folder, which is usually C:\Windows\Start Menu or C:\Documents and Settings\{User name}\Start Menu on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu on Windows Vista and 7.)

Other System Modifications

This Trojan adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\{RANDOM_NUMBERS}
Grep = {RANDOM_HEX_VALUES}

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}.{BLOCKED}.239.71/set.php?url=5&affid=51200&sts=&win=Windows XP+3.0
  • http://{BLOCKED}twebcenter.com/

It deletes the initially executed copy of itself

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

7.168.02

FIRST VSAPI PATTERN DATE:

14 May 2010

VSAPI OPR PATTERN File:

7.169.00

VSAPI OPR PATTERN Date:

15 May 2010

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

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.  
  • %Application Data%\{RANDOM_NUMBERS}

Step 4

Search and delete this file

[ Learn More ]
There may be some 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%Security Tool.lnk
  • %Start Menu%\Programs\Security Tool.lnk

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_LOCAL_MACHINE\SOFTWARE
    • {RANDOM_NUMBERS}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • {RANDOM_NUMBERS} = %Application Data%\{RANDOM_NUMBERS}\{RANDOM_NUMBERS}.exe

Step 6

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