Analysis by: Joselyn Canuela
ALIASES:

Trojan.Win32.Agent.nfaoky (Kaspersky), Emotet-FAL!9D3D6151063C (McAfee), TR/Crypt.Xpack.dwkff (Avira)

 PLATFORM:

Windows

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

  • Threat Type: Trojan Spy

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Trojan Spy 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

Arrival Details

This Trojan Spy 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 Spy drops the following copies of itself into the affected system and executes them:

  • %AppDataLocal%\Microsoft\Windows\dcomevent.exe

(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Autostart Technique

This Trojan Spy adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
dcomevent = "%AppDataLocal%\Microsoft\Windows\dcomevent.exe"

Other System Modifications

This Trojan Spy modifies the Internet Explorer Privacy Settings.

Other Details

This Trojan Spy connects to the following possibly malicious URL:

  • http://{BLOCKED}.{BLOCKED}.35.121:8080
  • http://{BLOCKED}.{BLOCKED}.142.250:443
  • http://{BLOCKED}.{BLOCKED}.199.223:8080
  • http://{BLOCKED}.{BLOCKED}.145.224:8080

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.556.07
FIRST VSAPI PATTERN DATE: 26 Jul 2017
VSAPI OPR PATTERN File: 13.557.00
VSAPI OPR PATTERN Date: 27 Jul 2017

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

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

Identify and terminate files detected as TSPY_EMOTET.AUSJKI

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • dcomevent = "%AppDataLocal%\Microsoft\Windows\dcomevent.exe"

Step 5

Scan your computer with your Trend Micro product to delete files detected as TSPY_EMOTET.AUSJKI. 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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