Analysis by: Ryan Paolo Maglaque
 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: Dropped by other malware, Downloaded from the Internet

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.

  TECHNICAL DETAILS

File Size: 563,200 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 09 Feb 2017
Payload: Connects to URLs/IPs

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 adds the following processes:

  • rundll32.exe

It injects codes into the following process(es):

  • rundll32.exe

Autostart Technique

This Backdoor adds and runs the following services:

  • netsrv

Backdoor Routine

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

  • Create, change, or remove directory
  • Create or open a file
  • Create or terminate a process
  • Inject code to a process
  • Start a service
  • Create or purge kerberos ticket
  • Use powershell
  • Sleep

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

  • {BLOCKED}o.net
  • {BLOCKED}n.com
  • {BLOCKED}oft-tool.com
  • {BLOCKED}apps-live.com
  • {BLOCKED}kernel.com
  • {BLOCKED}erserviceapi.info
  • {BLOCKED}apps-live.net

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.498.05
FIRST VSAPI PATTERN DATE: 27 Jun 2017
VSAPI OPR PATTERN File: 13.499.00
VSAPI OPR PATTERN Date: 28 Jun 2017

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

Disable this malware service

[ Learn More ]
  •  
    • netsrv

Step 5

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


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