Trojan.MSIL.MALLOX.0NA103B224
Ransom:MSIL/Mallox.LL!MTB (MICROSOFT)
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
Downloaded from the Internet, Dropped by other malware
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.
TECHNICAL DETAILS
1,116,672 bytes
EXE
Yes
05 Feb 2024
Connects to URLs/IPs, Drops files, Modifies system registry
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 drops the following copies of itself into the affected system:
- %Application Data%\ytrfhgref.exe
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
It drops the following files:
- %User Temp%\{Random Characters}
(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:
- %Windows%\Microsoft.NET\Framework\v4.0.30319\MSBuild.exe
- %Windows%\Microsoft.NET\Framework\v4.0.30319\MSBuild.exe /stext "%User Temp%\{Random Characters}"
- %System%\WScript.exe" "%User Temp%\{Random Characters}.vbs
(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %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).. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
ytrfhgref = %Application Data%\ytrfhgref.exe
Other System Modifications
This Trojan modifies the following registry entries:
HKEY_CURRENT_USER\Software\Rmc-A49MY7
exepath = {Hex values}
HKEY_CURRENT_USER\Software\Rmc-A49MY7
licence = {Random numbers}
HKEY_CURRENT_USER\Software\Rmc-A49MY7
time = {Random numbers}
Other Details
This Trojan adds the following registry keys:
HKEY_CURRENT_USER\Software\Rmc-A49MY7
It connects to the following possibly malicious URL:
- http://{BLOCKED}gin.net/json.gp
SOLUTION
9.800
19.140.01
05 Feb 2024
19.141.00
06 Feb 2024
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.XXPE50FFF077
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
Restart in Safe Mode
Step 4
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 5
Search and delete this file
- %Application Data%\ytrfhgref.exe
- %User Temp%\{Random Characters}
Step 6
Delete this registry key
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\Rmc-A49MY7
Step 7
Delete this registry value
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
- ytrfhgref = %Application Data%\ytrfhgref.exe
- ytrfhgref = %Application Data%\ytrfhgref.exe
- In HKEY_CURRENT_USER\Software\Rmc-A49MY7
- exepath = {Hex values}
- exepath = {Hex values}
- In HKEY_CURRENT_USER\Software\Rmc-A49MY7
- licence = {Random numbers}
- licence = {Random numbers}
- In HKEY_CURRENT_USER\Software\Rmc-A49MY7
- time = {Random numbers}
- time = {Random numbers}
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as Trojan.MSIL.MALLOX.0NA103B224. 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 this Knowledge Base page for more information.
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