RANSOM_YAFCOOKIE.A
Ransom.Yafcookie.Gen!c(AegisLab)
Windows
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Trojan
Destructiveness: No
Encrypted: Yes
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.
Installation
This Trojan drops the following files:
- %User Temp%\fukjdJd1shjdhsjd2.tmp - contains the number of instances the malware was executed
- {drive letter:}\test. log - contains the strings Status OK!
- %User Temp%\3h88jdRdhsufjdJj3.tmp - list of encrypted files
(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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.)
Other Details
This Trojan does the following:
- It avoids encrypting files with the following extensions:
- .bat
- .com
- .dll
- .exe
- .ico
- .inf
- .ini
- .log
- .sys
- .url
- It adds the "YouAreFucked" string at the beginning of the encrypted files' binary .
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
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
Restart in Safe Mode
Step 4
Search and delete this file
- %User Temp%\fukjdJd1shjdhsjd2.tmp
- %User Temp%\3h88jdRdhsufjdJj3.tmp
- {drive letter:}\test. log
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as RANSOM_YAFCOOKIE.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.
Step 6
Restore encrypted files from backup.
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