Analysis by: Joshua Paul Ignacio

ALIASES:

TrojanDropper:PowerShell/Cobacis.B (MICROSOFT)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

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

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 3,586 bytes
File Type: PS1
Memory Resident: Yes
Initial Samples Received Date: 26 Feb 2021
Payload: Connects to URLs/IPs

Arrival Details

This Trojan 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 Trojan injects codes into the following process(es):

  • powershell.exe

Other Details

This Trojan does the following:

  • It connects to the following URL to download and execute code in memory:
    • {BLOCKED}.{BLOCKED}.11.229

However, as of this writing, the said sites are inaccessible.

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 16.374.05
FIRST VSAPI PATTERN DATE: 26 Nov 2020
VSAPI OPR PATTERN File: 16.375.00
VSAPI OPR PATTERN Date: 27 Nov 2020

Step 1

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.

Step 2

Scan your computer with your Trend Micro product to delete files detected as Trojan.PS1.COBEACON.SMYXAK-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 the following Trend Micro Support pages for more information:


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