WORM_AINSLOT.DAF

May 21, 2013
 ALIASES:

Worm:Win32/Ainslot.A (Microsoft); W32/Ainslot.c (McAfee); W32.Shadesrat (Symantec); Trojan-FakeAV.Win32.Windef.nwd (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse MSIL.EBP (AVG)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • 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.

  TECHNICAL DETAILS

File Size:

739,328 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

21 May 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 drops the following copies of itself into the affected system:

  • %User Temp%\WinDefender.Exe

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

Other System Modifications

This worm modifies the following file(s):

  • %Application Data%\GDIPFONTCACHEV1.DAT

(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 deletes the following files:

  • %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.204.34046
  • %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.204.34046
  • %User Profile%\v2.0.50727.42\security.config.cch.204.34187

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

It adds the following registry keys:

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
SrvID\ID

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
INSTALL\DATE

It adds the following registry entries:

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
SrvID\ID
IG2OMGD5BH = "Extanded"

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
INSTALL\DATE
IG2OMGD5BH = "January 28, 2013"

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
GDIPlus
FontCachePath = "%Application Data%"

(Note: The default value data of the said registry entry is %User Profile%\Local Settings\Application Data.)

Dropping Routine

This worm drops the following files:

  • %User Temp%\RJIPe.vbs
  • %User Profile%\Application Data\Extanded.exe

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

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.300

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

Delete this registry key

[ 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\VB and VBA Program Settings\SrvID
    • ID
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\INSTALL
    • DATE

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\VB and VBA Program Settings\SrvID\ID
    • IG2OMGD5BH = "Extanded"
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\INSTALL\DATE
    • IG2OMGD5BH = "January 28, 2013"

Step 4

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\GDIPlus
    • From: FontCachePath = "%Application Data%"
      To: FontCachePath = ""%User Profile%\Local Settings\Application Data""

Step 5

Search and delete these components

[ Learn More ]
There may be some components 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.
  • %User Temp%\RJIPe.vbs
  • %User Profile%\Application Data\Extanded.exe

Step 6

Scan your computer with your Trend Micro product to delete files detected as WORM_AINSLOT.DAF. 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 7

Restore deleted/modified files and/or registry entries from backup

*Note: Only Microsoft-related files/keys/values will be restored. If this malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.

    • %Application Data%\GDIPFONTCACHEV1.DAT

Step 8

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.204.34046
  • %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.204.34046
  • %User Profile%\v2.0.50727.42\security.config.cch.204.34187


Did this description help? Tell us how we did.