WORM_DDOSER.A
Backdoor:Win32/Darkddoser.D(Microsoft), Backdoor.Win32.Fynloski(Ikarus)
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: Yes
In the wild: Yes
OVERVIEW
Downloaded from the Internet, Dropped by other malware, Propagates via removable drives
This worm 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.
It executes commands from a remote malicious user, effectively compromising the affected system.
TECHNICAL DETAILS
183,632 bytes
EXE
Yes
07 Nov 2012
Connects to URLs/IPs, Steals information
Arrival Details
This worm 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 and executes them:
- %Application Data%\Microsoft\svchost.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.)
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- HelloDDoser
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
svchost.exe = "%Application Data%\Microsoft\svchost.exe"
Propagation
This worm drops the following copy(ies) of itself in all removable drives:
- {Drive Letter}:\svchost.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]
shell=verb
open=svchost.exe
action=Open folder to view files
shell\open=Open
icon=%SystemRoot%\system32\SHELL32.dll,4
Backdoor Routine
This worm opens the following port(s) where it listens for remote commands:
- TCP port 3085
It executes the following commands from a remote malicious user:
- Terminate self
- Sleep
- Update itself
- Download Files
- Download arbitrary files
- Upload arbitrary files
- Start SYN flood
- Start UDP flood
It connects to the following URL(s) to send and receive commands from a remote malicious user:
- {BLOCKED}acks234.{BLOCKED}p.info
Information Theft
This worm attempts to get stored information such as user names, passwords, and hostnames from the following browsers:
- Mozilla Firefox
SOLUTION
9.300
9.514.04
08 Nov 2012
9.515.00
09 Nov 2012
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
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
- svchost.exe = "%Application Data%\Microsoft\svchost.exe"
- svchost.exe = "%Application Data%\Microsoft\svchost.exe"
Step 4
Search and delete AUTORUN.INF files created by WORM_DDOSER.A that contain these strings
[autorun]
shell=verb
open=svchost.exe
action=Open folder to view files
shell\open=Open
icon=%SystemRoot%\system32\SHELL32.dll,4
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_DDOSER.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.
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