Analysis by: Vincent Martin Hermosura
 Modified by: Mark Joseph Manahan
ALIASES:

a variant of Win32/Sacto.G trojan (Eset) ,Generic (Panda) ,Trojan.Win32.Generic!BT (Sunbelt)

 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:
 INFORMATION EXPOSURE:

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware

This backdoor may be dropped by other malware.

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

It gathers certain information on the affected computer.

  TECHNICAL DETAILS

File Size: 95,232 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 21 May 2014
Payload: Collects system information

Arrival Details

This backdoor may be dropped by the following malware:

  • TROJ_ARTIEF.KJC

Autostart Technique

This backdoor drops the following file(s) in the Windows Common Startup folder to enable its automatic execution at every system startup:

  • %User Startup%\Office Start.lnk

(Note: %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.)

Backdoor Routine

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

  • Process Manipulation (List, Terminate & Create)
  • File Manipulation (List, Delete, Creation Time)
  • Retrieve Volume/Drive Information
  • Visit URL / Download File
  • Delay (10s)

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

  • http://{BLOCKED}sean.{BLOCKED}p.net/{numerical value}
  • http://{BLOCKED}njia.{BLOCKED}p.net/{numerical value}

Information Theft

This backdoor gathers the following information on the affected computer:

  • Processor/System Architecture Information
  • Computer Name/Username
  • Network Information
  • Proxy Settings

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 10.808.03
FIRST VSAPI PATTERN DATE: 21 May 2014

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

Remove the malware/grayware file that dropped/downloaded BKDR_SACTO.FAM. (Note: Please skip this step if the threat(s) listed below have already been removed.)

    • TROJ_ARTIEF.KJC

Step 3

Identify and terminate files detected as BKDR_SACTO.FAM

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

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.  
  • %User Startup%\Office Start.lnk

Step 5

Scan your computer with your Trend Micro product to delete files detected as BKDR_SACTO.FAM. 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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