Trojan.JS.DOWNLOADER.K
HEUR:Trojan-Downloader.Script.SLoad.gen (KASPERSKY)
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.
It does not have any propagation routine.
It does not have any backdoor routine.
As of this writing, the said sites are inaccessible.
It does not have any information-stealing capability.
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 drops the following files:
- %User Temp%\{Random Characters}.\{Random 3 Characters}.ps1 → Deleted afterward
- %User Temp%\{Random Characters}.\{Random 3 Characters}.psm1 → Deleted afterward
- %AppDataLocal%\Tempa.exe
- %AppDataLocal%\Microsoft\Windows\PowerShell\StartupProfileData-NonInteractive
(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).. %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
It adds the following processes:
- "%System%\WindowsPowerShell\v1.0\powershell.exe" {Malicious code}
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
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:
- http://{BLOCKED}xample.com/malware.exe
As of this writing, the said sites are inaccessible.
Information Theft
This Trojan does not have any information-stealing capability.
Other Details
This Trojan does not exploit any vulnerability.
SOLUTION
Step 1
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 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
Search and delete these files
- %User Temp%\{Random Characters}.\{Random 3 Characters}.ps1
- %User Temp%\{Random Characters}.\{Random 3 Characters}.psm1
- %AppDataLocal%\Tempa.exe
- %AppDataLocal%\Microsoft\Windows\PowerShell\StartupProfileData-NonInteractive
Step 4
Scan your computer with your Trend Micro product to delete files detected as Trojan.JS.DOWNLOADER.K. 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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