BKDR_INVADER.B

 Analysis by: Joachim Suico

 ALIASES:

W32/Invader.U!tr (Fortinet); HEUR:Trojan.Win32.Invader (Kaspersky); Trojan.Invader! (Agnitum)

 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • 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 deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size:

254,464 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

16 Apr 2015

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 copies of itself into the affected system and executes them:

  • %Program Files%\Windows NT\Accessories\nt\GoogleUpdate.exe (If affected user is administrator)
  • %User Profile%\Applications\GoogleUpdate.exe (Otherwise)

(Note: %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.. %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.)

Autostart Technique

This backdoor registers as a system service to ensure its automatic execution at every system startup by adding the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\SENSS

Backdoor Routine

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

  • Download and execute files
  • Capture screenshots
  • Log mouse and keyboard actions
  • Update itself
  • Open a remote shell
  • Terminate processes
  • Enumerate network shares
  • Enumerate drives
  • Uninstall itself

It connects to the following URL(s) to send and receive commands from a remote malicious user:

  • bbs.{BLOCKED}es.com:80
  • img.{BLOCKED}lves.com:8080
  • domain.{BLOCKED}es.com:443

Other Details

This backdoor deletes the initially executed copy of itself

  SOLUTION

Minimum Scan Engine:

9.750

FIRST VSAPI PATTERN FILE:

11.710.06

FIRST VSAPI PATTERN DATE:

16 Apr 2015

VSAPI OPR PATTERN File:

11.711.00

VSAPI OPR PATTERN Date:

17 Apr 2015

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

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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.

 
  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\SENSS

Step 5

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