Trojan.Win32.RANUMBOT.SYFV
Trojan:Win32/RanumBot!rfn (MICROSOFT)
Windows

Threat Type: Trojan
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It does not have any propagation routine.
It does not have any backdoor routine.
TECHNICAL DETAILS
Arrival Details
This Trojan 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 adds the following folders:
- %User Temp%\csrss
- %User Temp%\csrss\wup
- %User Temp%\csrss\wup\xarch
(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).)
It adds the following processes:
- %User Temp%\csrss\wup\xarch\wup.exe
- if %Windows%\rss\csrss.exe exists:
- %Windows%\rss\csrss.exe -hide {PID of wup.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).. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- Global\xwupMUTEX31337
- Global\xmrigMUTEX31337 → checking for running downloaded wup.exe
Propagation
This Trojan does not have any propagation routine.
Backdoor Routine
This Trojan does not have any backdoor routine.
Rootkit Capabilities
This Trojan does not have rootkit capabilities.
Download Routine
This Trojan connects to the following website(s) to download and execute a malicious file:
- If OS is 32 bit:
- https://{BLOCKED}ndiff.com/{16 randomly generated hex values}/xme32-635-gcc.exe
- http://x.{BLOCKED}ndiff.com/{16 randomly generated hex values}/xme32-635-gcc.exe
- If OS is 64 bit:
- https://{BLOCKED}ndiff.com/{16 randomly generated hex values}/xme64-635.exe
It saves the files it downloads using the following names:
- %User Temp%\csrss\wup\xarch\wup.exe
- If 32 bit, detected as Coinminer.Win32.MALXMR.SMBM4
- If 64 bit, detected as Coinminer.Win64.MALXMR.TIAOODGF
(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).)
Other Details
This Trojan does the following:
- Continues with routine if one of the following keys and corresponding entries exists:
- HKEY_CURRENT_USER\{User SID}\Software\Microsoft\TestApp
UUID = {string data}
OSArchitecture = {64 or 32}
Servers = {multi string data} - HKEY_CURRENT_USER\{User SID}\Software\Microsoft\{hex generated from SID}
UUID = {string data}
OSArchitecture = {64 or 32}
Servers = {multi string data}
- HKEY_CURRENT_USER\{User SID}\Software\Microsoft\TestApp
- attempts to hide wup.exe process using the following malicious component exists:
- %Windows%\rss\csrss.exe
(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)
It does not exploit any vulnerability.
SOLUTION
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.XXPE50FFF039
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
Search and delete these files
- %User Temp%\csrss\wup\xarch\wup.exe
Step 5
Search and delete this folder
- %User Temp%\csrss
- %User Temp%\csrss\wup
- %User Temp%\csrss\wup\xarch
Step 6
Scan your computer with your Trend Micro product to delete files detected as Trojan.Win32.RANUMBOT.SYFV. 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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