TROJ_MERETAM.A
Trojan.Win32.Yakes.wtyq (Kaspersky), Trojan-FPRI!DD197CA3E27D (McAfee)
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted:
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.
TECHNICAL DETAILS
342,528 bytes
EXE
No
16 Jul 2018
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 and executes them:
- %Application Data%\msnet\{Malware filename}.exe
(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)
It drops the following files:
- %Application Data%\Microsoft\Crypto\RSA\{Random name}\{Random GUID}
- %System%\Tasks\MsSystemWatcher
- %Application Data%\Microsoft\Windows\Recent\CustomDestinations\d93f411851d7c929.customDestinations-ms
(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
It adds the following processes:
- cmd.exe /c sc delete WinDefend
- cmd.exe /c sc stop WinDefend
- cmd.exe /c powershell Set-MpPreference -DisableRealtimeMonitoring $true
Other System Modifications
This Trojan modifies the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows Defender
DisableAntiSpyware = 1
(Note: The default value data of the said registry entry is 0.)
SOLUTION
9.850
14.386.01
17 Jul 2018
14.387.00
18 Jul 2018
Step 1
Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.
Step 2
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 3
Restore this modified 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_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender
- From: DisableAntiSpyware = "1"
To: DisableAntiSpyware = "0"
- From: DisableAntiSpyware = "1"
Step 4
Search and delete these files
- %Application Data%\Microsoft\Crypto\RSA\{Random name}\{Random GUID}
- %Application Data%\Microsoft\Windows\Recent\CustomDestinations\d93f411851d7c929.customDestinations-ms
- %System%\Tasks\MsSystemWatcher
Step 5
Scan your computer with your Trend Micro product to delete files detected as TROJ_MERETAM.A. 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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