BKDR_TARTOBER.A

May 26, 2013
 ALIASES:

Backdoor:Win32/Tartober.A (Microsoft); Generic Dropper!f2p (McAfee); Trojan.Gen (Symantec); Trojan.Win32.Genome.aiiop (Kaspersky); Trojan.Win32.Generic.pak!cobra (Sunbelt); Trojan horse Downloader.Generic13.QPO (AVG)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This backdoor 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 itself after execution.

  TECHNICAL DETAILS

File Size:

123,904 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

14 Mar 2013

Arrival Details

This backdoor 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 backdoor creates the following folders:

  • %User Temp%\~hf~

(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 backdoor modifies the following file(s):

  • %User Profile%\Application Data\Microsoft

(Note: %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 deletes the following files:

  • %Temporary Internet Files%\Content.IE5\ZSGKJKO6\downloads[1].htm
  • %Temporary Internet Files%\Content.IE5\ZDGZNKA5\downloads[1].htm

(Note: %Temporary Internet Files% is the Temporary Internet Files folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temporary Internet Files on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Microsoft\Windows\Temporary Internet Files on Windows Vista and 7.)

Dropping Routine

This backdoor drops the following files:

  • %User Profile%\Templates\adobe_sl.exe
  • %User Startup%\adobe_sl.lnk
  • %User Profile%\Microsoft\Crypto
  • %User Profile%\Crypto\DSS
  • %User Profile%\DSS\S-1-5-21-1645522239-1292428093-682003330-1003

(Note: %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.. %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.)

Other Details

This backdoor deletes itself after execution.

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

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 Profile%\Templates\adobe_sl.exe
  • %User Startup%\adobe_sl.lnk
  • %User Profile%\Microsoft\Crypto
  • %User Profile%\Crypto\DSS
  • %User Profile%\DSS\S-1-5-21-1645522239-1292428093-682003330-1003

Step 3

Search and delete this folder

[ 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.
  • %User Temp%\~hf~

Step 4

Scan your computer with your Trend Micro product to delete files detected as BKDR_TARTOBER.A. 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 5

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.

    • %User Profile%\Application Data\Microsoft

Step 6

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.

  • %Temporary Internet Files%\Content.IE5\ZSGKJKO6\downloads[1].htm
  • %Temporary Internet Files%\Content.IE5\ZDGZNKA5\downloads[1].htm


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