TROJ_RANSOM.CRDA
Trojan.Ransomcrypt (Norton)
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
Threat Type: Trojan
Destructiveness: No
Encrypted: No
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
666,112 bytes
EXE
Yes
10 Jan 2013
Encrypts files
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 file(s)/component(s):
- {malware path}\privkey.bin - Stores the generated private RSA key
- {malware path}\pubkey.bin - Stores the generated public RSA key
- {malware path}\cryptedcount.txt - Lists count of encrypted files
- {malware path}\countdown.txt
NOTES:
This Trojan avoids encrypting files with the following file extensions:
- .RANS
- .EXE
- .DLL
- .INI
- .VXD
- .DRV
It avoids encrypting files/directory with the following strings in their file name/folder name:
- privkey.bin
- pubkey.bin
- countdown.txt
- cryptedcount.txt
- $Recycle.Bin
It saves the encrypted files using .rans as its file extension.
It searches for files to encrypt in fixed drives and remote (network) drives.
It sends the generated RSA keys to its C&C server.
It has anti-debugging capabilities.
SOLUTION
9.700
10.532.08
10 Jan 2014
10.533.00
11 Jan 2014
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 and note files detected as TROJ_RANSOM.CRDA
Step 3
Restart in Safe Mode
Step 4
Search and delete these files
- {malware path}\privkey.bin
- {malware path}\pubkey.bin
- {malware path}\countdown.txt
- {malware path}\cryptedcount.txt
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_RANSOM.CRDA. 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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