Analysis by: Bren Matthew Ebriega
ALIASES:

Trojan.Win32.Agent.xadhmw (KASPERSKY); W32/Agent.KIMSQBJ!tr (FORTINET)

 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

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

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 runs certain commands that it receives remotely from a malicious user. Doing this puts the affected computer and information found on the computer at greater risk. It connects to a website to send and receive information. However, as of this writing, the said sites are inaccessible.

It creates an event.

  TECHNICAL DETAILS

File Size: 279,552 bytes
File Type: DLL
Memory Resident: Yes
Initial Samples Received Date: 01 Jun 2020
Payload: Drops files, 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 drops the following files:

  • %Application Data%\Microsoft\Protect\Windows\DMI86229.DAT → Contains the encrypted configuration and URL/IP's

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

It creates the following folders:

  • %Application Data%\Microsoft\Protect\Windows

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

Backdoor Routine

This Backdoor executes the following command(s) from a remote malicious user:

  • Execute commands and executables
  • Write Files
  • Read Files
  • Update Configuration
  • Upload Configuration Data

It connects to the following websites to send and receive information:

  • https://{BLOCKED}.{BLOCKED}.67.199/{generated value}
  • https://{BLOCKED}.{BLOCKED}.153.236/{generated value}
  • https://www.{BLOCKED}rmantic.com/{generated value}
  • https://www.{BLOCKED}olisa.com/{generated value}

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

Other Details

This Backdoor does the following:

  • It attempts to connect to its C&C using the following methods:
    • Via Configured Proxy
    • Via Web Proxy Auto-Discovery Protocol
    • Via Internet Explorer Proxy
    • Via Firefox Proxy
    • Via Auto Proxy
    • Via Pre-Configured Proxy

It creates the following event(s):

  • Local\{B47D655A-66F9-4A3C-BCE1-75ACBF3821C}

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 15.908.03
FIRST VSAPI PATTERN DATE: 03 Jun 2020
VSAPI OPR PATTERN File: 15.909.00
VSAPI OPR PATTERN Date: 03 Jun 2020

Step 1

Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:

    • TROJ.Win32.TRX.XXPE50FLM010

Step 2

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 3

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 4

Restart in Safe Mode

[ Learn More ]

Step 5

Identify and terminate files detected as Backdoor.Win32.SAGRUNEX.E

[ 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 6

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %Application Data%\Microsoft\Protect\Windows

Step 7

Search and delete this file

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.  
  • %Application Data%\Microsoft\Protect\Windows\DMI86229.DAT

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Backdoor.Win32.SAGRUNEX.E. 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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