Analysis by: Maureen Reyes
 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. It may be dropped by other malware.

It does not have any file infection routine.

It does not have any propagation routine.

It does not have any backdoor routine.

It does not have any downloading capability.

It does not have any information-stealing capability.

  TECHNICAL DETAILS

File Size: 3,224 bytes
File Type: VBS
Memory Resident: No
Initial Samples Received Date: 22 Jul 2019

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.

It may be dropped by the following malware:

Infection Points

This Trojan does not have any file infection routine.

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Rootkit Capabilities

This Trojan does not have rootkit capabilities.

Download Routine

This Trojan does not have any downloading capability.

Information Theft

This Trojan does not have any information-stealing capability.

Other Details

This Trojan does the following:

  • Decodes %AppDataLocal%\tmicro\tmicro_analyzer.exe using the following command:
    "cmd.exe /c certutil -f -decode "%AppDataLocal%\tmicro\tmicro_analyzer.exe.dat" "%AppDataLocal%\tmicro\tmicro_analyzer.exe""
  • Runs the malware Backdoor.Win32.COBALT.AI, using the command below:
    "cmd .exe /c %AppDataLocal%\tmicro\tmicro_analyzer.exe"

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 15.250.06
FIRST VSAPI PATTERN DATE: 22 Jul 2019
VSAPI OPR PATTERN File: 15.251.00
VSAPI OPR PATTERN Date: 23 Jul 2019

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.VBS.COBALT.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 the following Trend Micro Support pages for more information:


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