Analysis by: Francesca Villasanta
ALIASES:

UDS:Trojan-Proxy.Win32.Sybici.aam (KASPERSKY); Trojan:Win32/Coroxy.BL!MTB (MICROSOFT)

 PLATFORM:

Windows

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

  • Threat Type: Trojan Spy

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

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

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.

It executes commands from a remote malicious user, effectively compromising the affected system. It connects to a website to send and receive information.

It gathers certain information on the affected computer.

  TECHNICAL DETAILS

File Size: 18,000 bytes
File Type: PS1
Memory Resident: Yes
Initial Samples Received Date: 09 Oct 2023
Payload: Connects to URLs/IPs, Collects system information, Downloads files, Deletes files

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 adds the following mutexes to ensure that only one of its copies runs at any one time:

  • {BLOCKED}ones.com

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
socks5 = powershell.exe -windowstyle hidden -Command "& '{Malware Path}\{Malware Filename}'"

Backdoor Routine

This Trojan Spy executes the following commands from a remote malicious user:

  • Download and execute EXE files.

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

  • via TCP:
    • {BLOCKED}ones.com:64443

It connects to the following URL(s) to send and receive commands from a remote malicious user:

  • via TCP:
    • {BLOCKED}ones.com:64443

Download Routine

This Trojan Spy saves the files it downloads using the following names:

  • %User Temp%\{Random Characters}.exe

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

Information Theft

This Trojan Spy gathers the following information on the affected computer:

  • Username
  • Volume Serial Number

Other Details

This Trojan Spy does the following:

  • It uninstalls the autorun registry created before terminating itself.

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 18.776.02
FIRST VSAPI PATTERN DATE: 24 Oct 2023
VSAPI OPR PATTERN File: 18.777.00
VSAPI OPR PATTERN Date: 25 Oct 2023

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.XXPE50FFF073

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

Identify and terminate files detected as TrojanSpy.Win32.SYSTEMBC.FBV

[ 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 5

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
    • socks5 = powershell.exe -windowstyle hidden -Command & '{Malware Path}\{Malware Filename}'

Step 6

Search and delete files detected as TrojanSpy.Win32.SYSTEMBC.FBV

[ 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.
  • %User Temp%\{Random Characters}.exe

Step 7

Scan your computer with your Trend Micro product to delete files detected as TrojanSpy.Win32.SYSTEMBC.FBV. 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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