TrojanSpy.Win32.RYUK.B

February 10, 2020
 Analysis by: Clive Fuentebella
 ALIASES:

Win32:Trojan-gen (AVAST); W32/GenKryptik.ECNA!tr (FORTINET)

 PLATFORM:

Windows

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

  • Threat Type: Trojan Spy

  • Destructiveness: No

  • Encrypted: Yes

  • 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.

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

  TECHNICAL DETAILS

File Size:

654,336 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

09 Feb 2020

Payload:

Connects to URLs/IPs

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.

Other Details

This Trojan Spy uploads files to the following website(s):

  • {BLOCKED}.{BLOCKED}.108.141
  • {BLOCKED}.{BLOCKED}.1.57

It does the following:

  • It avoids files with the following strings in its file path:
    • $Recycle.Bin
    • $Windows
    • .ascx
    • .asp
    • .bmp
    • .browser
    • .cab
    • .cat
    • .cdx
    • .chm
    • .config
    • .contact
    • .css
    • .db
    • .ddf
    • .dic
    • .din
    • .dll
    • .exe
    • .gif
    • .h
    • .ibd
    • .icml
    • .inf
    • .ini
    • .iobj
    • .ipdb
    • .js
    • .lib
    • .little
    • .lnk
    • .log
    • .microsoft
    • .mp3
    • .msc
    • .msi
    • .new
    • .oem
    • .pem
    • .png
    • .ps1
    • .pyd
    • .qml
    • .rsm
    • .sdi
    • .search-ms
    • .sqlite
    • .sys
    • .thmx
    • .tif
    • .tmp
    • .ttf
    • .txmx
    • .url
    • .vicache
    • .wbcat
    • .wbverify
    • .wim
    • .wmv
    • .xml
    • .xpi
    • \Users\Public\Pictures
    • cached
    • Firefox
    • Intel
    • log
    • microsoft
    • Microsoft
    • Mozilla
    • MySQL
    • NTUSER
    • Package Cache
    • PerfLogs
    • ppsm
    • ppt
    • Program Files
    • ProgramData
    • PUBLIC
    • readme
    • RyukReadMe.txt
    • Sample Music
    • Sample Pictures
    • Tor Browser
    • UNIQUE_ID_DO_NOT_REMOVE
    • Windows
    • windows
    • wtv
  • It stores files with the following strings in its filename:
    • 10-Q
    • 10-SB
    • 10Q
    • 8K
    • agent
    • bribery
    • bureau
    • censored
    • clandestine
    • confident
    • contraband
    • convictMilitary
    • court
    • CSI
    • csi
    • cyber
    • document
    • drug
    • EDGAR
    • embeddedspy
    • Engeneering
    • explosive
    • FBI
    • fbi
    • federal
    • fraud
    • government
    • gun
    • hack
    • hidden
    • important
    • investigation
    • marketwired
    • military
    • N-CSR
    • NATO
    • Nato
    • newswire
    • NSA
    • operation
    • pass
    • private
    • radar
    • radio
    • scheme
    • Secret
    • SECURITY
    • spy
    • submarine
    • Submarinesecret
    • suspect
    • tactical
    • traitor
    • treasonrestricted
    • undercover
    • victim
    • war
  • It stores files with the following strings in its contents (provided their extensions are doc, docb, docx, jpg, pdf, xls, xlsx, wallet.dat):
    • 10-Q
    • agent
    • agreement
    • attack
    • backdoorundercover
    • balance
    • bribery
    • bureau
    • censored
    • checking
    • clandestine
    • clandestine
    • Clearance
    • Compilation
    • compromate
    • concealed
    • confident
    • confident
    • contraband
    • contract
    • convict
    • court
    • cyber
    • defence
    • document
    • drug
    • embeddedspy
    • Emma
    • Engeneering
    • explosive
    • federal
    • finance
    • fraud
    • government
    • hack
    • hidden
    • IBAN
    • illegal
    • investigation
    • Isabella
    • James
    • letter
    • Liam
    • license
    • Logan
    • mail
    • marketwired
    • military
    • NATO
    • Nato
    • newswire
    • Noah
    • Olivia
    • operation
    • passport
    • personal
    • personal
    • privacy
    • private
    • radar
    • radio
    • report
    • restricted
    • routing
    • saving
    • scans
    • scheme
    • secret
    • secret
    • security
    • securityN-CSR10-SBEDGAR
    • Sophia
    • spy
    • statement
    • submarine
    • suspect
    • SWIFT
    • tactical
    • tank
    • traitor
    • treason
    • unclassified
    • seed
    • victim
    • William

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

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

15.676.04

FIRST VSAPI PATTERN DATE:

10 Feb 2020

VSAPI OPR PATTERN File:

15.677.00

VSAPI OPR PATTERN Date:

11 Feb 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.XXPE50FFF033

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

Scan your computer with your Trend Micro product to delete files detected as TrojanSpy.Win32.RYUK.B. 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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