WORM_VBKRYPT.BIR
Trojan:Win32/Provis!rts (Microsoft), Worm.Win32.VBKrypt.m (Kasperksy), Spyware.Keylogger (Symantec)
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: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This worm arrives via removable drives. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
TECHNICAL DETAILS
660,612 bytes
EXE
Yes
18 Apr 2013
Arrival Details
This worm arrives via removable drives.
It 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 worm drops the following copies of itself into the affected system:
- %Program Files%\{Random Folder Path}\{2 random char}{Random Filename}.exe
(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).)
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{2 random char}{Random Filename} = "%Program Files%\{Random Folder Path}\{2 random char}{Random Filename}.exe"
Other System Modifications
This worm adds the following registry keys:
HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
quafk5eeprtn5fazx
Propagation
This worm drops the following copy(ies) of itself in all removable drives:
- {drive letter}:\install.exe
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
The said .INF file contains the following strings:
[AutoRun]
open=install.exe
shell\open=Open(&O)
shell\open\Command=install.exe
shell\open\Default=1
shell\explore=Manage(&X)
shell\explore\Command=install.exe
Other Details
This worm connects to the following possibly malicious URL:
- 48140815{random 3 digit}}.go.3322.org
- 48140815{random 3 digit}.no-ip.info
- 48140815{random 3 digit}.blogspot.com
SOLUTION
9.300
9.864.02
18 Apr 2013
9.865.00
19 Apr 2013
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 WORM_VBKRYPT.BIR
Step 3
Restart in Safe Mode
Step 4
Delete this registry key
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\VB and VBA Program Settings
- quafk5eeprtn5fazx
- quafk5eeprtn5fazx
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- {2 random char}{Random Filename} = "%Program Files%\{Random Folder Path}\{2 random char}{Random Filename}.exe"
- {2 random char}{Random Filename} = "%Program Files%\{Random Folder Path}\{2 random char}{Random Filename}.exe"
Step 6
Search and delete AUTORUN.INF files created by WORM_VBKRYPT.BIR that contain these strings
- [AutoRun]
- open=install.exe
- shell\open=Open(&O)
- shell\open\Command=install.exe
- shell\open\Default=1
- shell\explore=Manage(&X)
- shell\explore\Command=install.exe
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_VBKRYPT.BIR. 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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