Analysis by: Clive Fuentebella
ALIASES:

N/A

 PLATFORM:

Windows, Linux, Mac

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

  • Threat Type: Potentially Unwanted Application

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

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

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

It executes commands from a remote malicious user, effectively compromising the affected system.

It takes advantage of certain vulnerabilities.

  TECHNICAL DETAILS

File Size: 197,739 bytes
File Type: PHP
Memory Resident: No
Payload: Connects to URLs/IPs, Steals information, Executes app

Arrival Details

This Potentially Unwanted Application 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 Potentially Unwanted Application drops the following files:

  • {Malware file path}\{Random}.php

Backdoor Routine

This Potentially Unwanted Application executes the following commands from a remote malicious user:

  • Manage file system (create file, read file, query file, move file, delete file, create directory)
  • Execute arbitrary commands (shell commands, PHP commands)
  • Gain root access through Dirty Cow exploit
  • Manage database
  • Zip/unzip files
  • Upload files
  • Get user credentials
  • Reset cPanel passwords
  • Create SMTP/RDP/mailer
  • Brute-force FTP credentials
  • Bind port to shell
  • Change backconnect configuration
  • Remove self
  • Deface index files
  • Configure redirects

Download Routine

This Potentially Unwanted Application accesses the following websites to download files:

  • https://www.{BLOCKED}r.org/version/?current={Version}
  • https://raw.githubusercontent.com/{BLOCKED}ox-com/0/main/leafmailer2.8.php

It saves the files it downloads using the following names:

  • {Malware file path}\adminer-{Random}.php
  • {Malware file path}\mailer-{Random}.php

Information Theft

Upon execution of the affected application, it gathers the following information:

  • Username
  • User account information
  • Memory information (actual size, size of free space)
  • Server information (loaded modules, phpinfo, server software, account settings)
  • Current working directory and permissions
  • Drives
  • Operating system information
  • IP address

Other Details

This Potentially Unwanted Application takes advantage of the following vulnerabilities:

  • CVE-2016-5195 (Dirty COW)

  SOLUTION

Minimum Scan Engine: 9.800
SSAPI PATTERN File: 2.467.00
SSAPI PATTERN Date: 02 Dec 2021

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

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.
  • {Malware file path}\adminer-{Random}.php
  • {Malware file path}\mailer-{Random}.php
  • {Malware file path}\{Random}.php

Step 4

Scan your computer with your Trend Micro product to delete files detected as PUA.PHP.AFoxTest.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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