Trojan.Win32.RANUMBOT.SYFV

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.

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}
• 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.