TROJ_COINMINER.AUSF

March 27, 2017
 Analysis by: Joselyn Canuela
 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • 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.

  TECHNICAL DETAILS

File Size:

139,979 bytes

File Type:

EXE

File Compression:

UPX

Memory Resident:

No

Initial Samples Received Date:

10 Nov 2016

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.

Other System Modifications

This Trojan adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Cygwin

HKEY_LOCAL_MACHINE\SOFTWARE\Cygwin\
Installations

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
ServicesForNFS

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Cygwin\
Installations
Cb0a42c2a1582349 = "\??\C:\ProgramData\AppCache"

NOTES:

This malware uses the system’s CPU to mine bitcoins.

It connects to the following mining pool(s):

  • stratum+tcp://xmr.{BLOCKED}ool.fr:3333

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

13.180.06

FIRST VSAPI PATTERN DATE:

10 Nov 2016

VSAPI OPR PATTERN File:

13.181.00

VSAPI OPR PATTERN Date:

11 Nov 2016

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

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.

 
  • HKEY_LOCAL_MACHINE\SOFTWARE\Cygwin
  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
  • ServicesForNFS

Step 4

Delete this registry value

[ 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.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Cygwin\Installations
    • Cb0a42c2a1582349 = "\??\C:\ProgramData\AppCache"

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_COINMINER.AUSF. 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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