BKDR_NAPOLAR.FS
Trojan:Win32/Napolar.A(Microsoft)
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: Backdoor
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It is injected into all running processes to remain memory resident.
It executes commands from a remote malicious user, effectively compromising the affected system. It connects to a website to send and receive information.
TECHNICAL DETAILS
Arrival Details
This backdoor 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 backdoor drops the following copies of itself into the affected system and executes them:
- %User Startup%\lsass.exe
(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.)
It is injected into all running processes to remain memory resident.
Autostart Technique
This backdoor drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:
- %User Startup%\lsass.exe
(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.)
Backdoor Routine
This backdoor executes the following commands from a remote malicious user:
- Steal information from a browser
- Open a browser and load a specific page
- Run a Tor service
- Download and execute file
- Perform DDOS attack
It connects to the following websites to send and receive information:
- http://www.{BLOCKED}answorld.in/index/user/forum/talks/
Information Theft
This backdoor gathers the following data:
- User name
- Computer name
NOTES:
This backdoor creates the following named pipe:
- \\.\pipe\napSolar
It can run a Tor service by dropping the following files:
- %Application Data%\tor.bin
- %Application Data%\torrc
It can also hook APIs.
With its rootkit functionality, it can block changes to the following registry keys:
- Microsoft\Windows\CurrentVersion\Run
- Microsoft\Windows NT\CurrentVersion\Windows\run
- Microsoft\Windows NT\CurrentVersion\Windows\load
- Microsoft\Windows\CurrentVersion\Policies\Explorer\run
- Microsoft\Windows NT\CurrentVersion\Winlogon
- Microsoft\Active Setup\Installed Components
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
Restart in Safe Mode
Step 3
Search and delete these files
- %Application Data%\tor.bin
- %Application Data%\torrc
Step 4
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_NAPOLAR.FS. 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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