Trojan:Win32/Dynamer!ac (Microsoft); Ransom.Satana (Malwarebytes); Trojan.Cryptolocker.AU (Symantec)
Windows
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 connects to certain websites to send and receive information. It deletes itself after execution.
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:
(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.)
It drops the following files:
(Note: %Desktop% is the desktop folder, where it usually is C:\Documents and Settings\{user name}\Desktop in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\Desktop in 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 and executes the following 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 System Modifications
This Trojan modifies the following file(s):
It adds the following registry entries as part of its installation routine:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{Random String} = %User Temp%\!satana!.txt
HKEY_CURRENT_USER\{Random}
BTC = {Bitcoin Wallet}
HKEY_CURRENT_USER\{Random}
E-mail = {Email Address}
Other Details
This Trojan connects to the following website to send and receive information:
It encrypts files with the following extensions:
It does the following:
It deletes itself after execution.
NOTES:
This ransomware displays the following ransom notes:
Step 1
Restore your system's Master Boot Record (MBR)
To restore your system's Master Boot Record (MBR):
• On Windows 2000, XP, and Server 2003:
• On Windows Vista, 7, and Server 2008:
• On Windows 8, 8.1, and Server 2012:
Step 2
Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.
Step 3
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 4
Delete this 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.
Step 5
Search and delete these files
Step 6
Scan your computer with your Trend Micro product to delete files detected as RANSOM_SATANA.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 7
Restore encrypted files from backup.