TROJ_RANSOM.USRI
Trojan-Ransom.Win32.Blocker.droa(Kaspersky),a variant of Win32/Kryptik.BUSQ trojan,Trojan horse Crypt2.CMZR(AVG)
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:
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 deletes the initially executed copy of itself.
TECHNICAL DETAILS
322,560 bytes
EXE
Yes
24 Feb 2014
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:
- {different locations}\BitCrypt.txt
- %Application Data%\bitcrypt.ccw
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)
It drops the following copies of itself into the affected system:
- %Application Data%\{random file name}.exe
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Bitcomint = %Application Data%\{random file name}.exe
Other System Modifications
This Trojan deletes the following registry keys:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Control\SafeBoot\Network
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Control\SafeBoot\Minimal
Other Details
This Trojan deletes the initially executed copy of itself
NOTES:
It may encrypt files.
SOLUTION
9.700
10.628.03
25 Feb 2014
10.629.00
26 Feb 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.USRI
Step 3
Identify and delete files detected as TROJ_RANSOM.USRI using the Recovery Console
Step 4
Search and delete these files
- {different locations}\BitCrypt.txt
- %Application Data%\bitcrypt.ccw
Step 5
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.
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- Bitcomint = %Application Data%\{random file name}.exe
- Bitcomint = %Application Data%\{random file name}.exe
Step 6
Scan your computer with your Trend Micro product to delete files detected as TROJ_RANSOM.USRI. 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 these deleted registry keys/values from backup
*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SafeBoot
- Network
- Network
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SafeBoot
- Minimal
- Minimal
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