Analysis by: Jennifer Gumban
 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

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 executes commands from a remote malicious user, effectively compromising the affected system. It connects to a website to send and receive information.

  TECHNICAL DETAILS

File Size: 404,992 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 26 Nov 2016
Payload: Connects to URLs/IPs, Compromises system security

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 drops the following file(s)/component(s):

  • %Application Data%\Microsoft\Windows\Tmp98871
  • %Application Data%\Microsoft\Windows\Tmp98872
  • %Application Data%\Microsoft\Windows\Tmpedi98871
  • %Application Data%\Microsoft\Windows\Tmpedo98871
  • %System%\ddd\a1.txt

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

Backdoor Routine

This backdoor executes the following commands from a remote malicious user:

  • General
  • DownloadFile
  • UploadFile
  • ChangeAliveSeconds

It connects to the following websites to send and receive information:

  • http://{BLOCKED}e.{BLOCKED}updater.com//Home/{url path}
    Where {url path} may be any of the following:
    • CheckConnection
    • SetCommandValue
    • Alive
    • SaveFile?commandId={command}&CmdResult={result}
    • GetFile?commandId={command}
    • SaveFile?commandId={command}

  SOLUTION

Minimum Scan Engine: 9.800

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

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Search and delete these files

[ 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.
  • %Application Data%\Microsoft\Windows\Tmp98871
  • %Application Data%\Microsoft\Windows\Tmp98872
  • %Application Data%\Microsoft\Windows\Tmpedi98871
  • %Application Data%\Microsoft\Windows\Tmpedo98871
  • %System%\ddd\a1.txt

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_ISMDOOR.C. 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 6

Scan your computer with your Trend Micro product to delete files detected as BKDR_ISMDOOR.C. 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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