Worm.Win32.Dorkbot_3aa236de87
Gen:Heur.ZOF.2 (BitDefender), Trojan.Win32.Diple.ufn (Kaspersky), Trojan.Win32.Encpk.pa (v) (VIPRE), Trojan.DownLoader3.59856 (DrWeb), Gen:Heur.ZOF.2 (B) (Emsisoft), PWS-Zbot.gen.ke (McAfee), Packed.Generic.341 (Symantec), Trojan.Win32.Diple (Ikarus), Gen:Heur.ZOF.2 (FSecure), Generic23.ALKF (AVG), Win32:Sality (Avast), TROJ_DROPR.SMIO (TrendMicro), Worm.Win32.Dorkbot.FD, WormDorkbot.YR, GenericUDPFlooder.YR, GenericIRCBot.YR, GenericMSNWorm.YR, GenericUSBInfector.YR, GenericDNSBlocker.YR, GenericAutorunWorm.YR, GenericSYNFlooder.YR, GenericInjector.YR, BankerGeneric.YR, GenericProxy.YR, GenericPhysicalDrive0.YR (Lavasoft MAS)
Behaviour: Banker, Trojan, Flooder, Worm, Packed, WormAutorun, IRCBot, MSNWorm, DNSBlocker, UDPFlooder, SYNFlooder, Trojan-Proxy, USBInfector
The description has been automatically generated by Lavasoft Malware Analysis System and it may contain incomplete or inaccurate information.
MD5: 3aa236de8736c3c82f59fddcb7e73e24
SHA1: f11ef878ae2673aebfbf6fd32b6cfed0a03690f8
SHA256: 04fa9b9c502bbbb973df2565b4ce68db0846ec509eddceaa483760c73baab6b5
SSDeep: 3072:bucn 3QlrrTzqCFk9DeOsaoz3TbLzIFN0wSmKt6gFEpVMZ4GghO1iTMPd229A6 :qcn3VeJfk3DzIFN0rxQk4zhO1iYPRJ
Size: 221184 bytes
File type: EXE
Platform: WIN32
Entropy: Not Packed
PEID: Armadillov171, MicrosoftVisualC, MicrosoftVisualCv50v60MFC, MicrosoftVisualC50, UPolyXv05_v6
Company: no certificate found
Created at: 2011-06-30 17:13:54
Analyzed on: WindowsXP SP3 32-bit
Summary:
Worm. A program that is primarily replicating on networks or removable drives.
Payload
| Behaviour | Description |
|---|---|
| WormAutorun | A worm can spread via removable drives. It writes its executable and creates "autorun.inf" scripts on all removable drives. The autorun script will execute the Worm's file once a user opens a drive's folder in Windows Explorer. |
| IRCBot | A bot can communicate with command and control servers via IRC channel. |
| MSNWorm | A worm can spread its copies through the MSN Messanger. |
| DNSBlocker | A program can block designated DNS servers for making it difficult for users to locate specific domains or web sites on the Internet. |
| UDPFlooder | This program can make a UDP flood. A UDP flood attack is a denial-of-service attack using the User Datagram Protocol (UDP). It can be initiated by sending a large number of UDP packets to random ports on a remote host. |
| SYNFlooder | This program can make a SYN flood. It is a form of denial-of-service attack in which an attacker sends a succession of SYN requests to a target's system in an attempt to consume enough server resources to make the system unresponsive to legitimate traffic. |
| Trojan-Proxy | This program can launch a proxy server (SOCKS4) on a designated TCP port. |
| USBInfector | A program can register a device notification with the help of RegisterDeviceNotification. So it is notified when a USB device is plugged and then the worm copies itself to the USB device plugged into the affected computer. |
Process activity
The Worm creates the following process(es):
%original file name%.exe:2000
Ctkmko.exe:1780
The Worm injects its code into the following process(es):
No processes have been created.
File activity
The process %original file name%.exe:2000 makes changes in the file system.
The Worm creates and/or writes to the following file(s):
%Documents and Settings%\%current user%\Application Data\Ctkmko.exe (1281 bytes)
Registry activity
The process %original file name%.exe:2000 makes changes in the system registry.
The Worm creates and/or sets the following values in system registry:
[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "F2 E5 A1 75 01 48 A9 93 5B 77 2C BA CA 55 D6 CE"
[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"AppData" = "%Documents and Settings%\%current user%\Application Data"
To automatically run itself each time Windows is booted, the Worm adds the following link to its file to the system registry autorun key:
[HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
"Ctkmko" = "%Documents and Settings%\%current user%\Application Data\Ctkmko.exe"
The process Ctkmko.exe:1780 makes changes in the system registry.
The Worm creates and/or sets the following values in system registry:
[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "55 C3 98 A2 02 23 55 EA B7 03 AF 1B 92 20 A6 44"
[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"AppData" = "%Documents and Settings%\%current user%\Application Data"
Network activity (URLs)
| URL | IP |
|---|---|
| hxxp://api.wipmania.com/ (ET POLICY External IP Lookup Attempt To Wipmania ) |  69.197.137.58 |
| update.jebac.net |  Unresolvable |
HOSTS file anomalies
No changes have been detected.
Rootkit activity
The Worm installs the following user-mode hooks in WININET.dll:
HttpSendRequestW
InternetWriteFile
HttpSendRequestA
The Worm installs the following user-mode hooks in ADVAPI32.dll:
RegCreateKeyExA
RegCreateKeyExW
The Worm installs the following user-mode hooks in WS2_32.dll:
send
getaddrinfo
The Worm installs the following user-mode hooks in kernel32.dll:
MoveFileA
CopyFileW
CopyFileA
MoveFileW
CreateFileW
CreateFileA
The Worm installs the following user-mode hooks in ntdll.dll:
LdrLoadDll
NtResumeThread
NtQueryDirectoryFile
NtEnumerateValueKey
Propagation
A worm can spread via removable drives. It writes its executable and creates "autorun.inf" scripts on all removable drives. The autorun script will execute the Worm's file once a user opens a drive's folder in Windows Explorer.
A program can register a device notification with the help of RegisterDeviceNotification. So it is notified when a USB device is plugged and then the worm copies itself to the USB device plugged into the affected computer.
A worm can spread its copies through the MSN Messanger.
Remove it with Ad-Aware
- Click (here) to download and install Ad-Aware Free Antivirus.
- Update the definition files.
- Run a full scan of your computer.
Manual removal*
- Scan a system with an anti-rootkit tool.
- Terminate malicious process(es) (How to End a Process With the Task Manager):
%original file name%.exe:2000
Ctkmko.exe:1780 - Delete the original Worm file.
- Delete or disinfect the following files created/modified by the Worm:
%Documents and Settings%\%current user%\Application Data\Ctkmko.exe (1281 bytes)
- Delete the following value(s) in the autorun key (How to Work with System Registry):
[HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
"Ctkmko" = "%Documents and Settings%\%current user%\Application Data\Ctkmko.exe" - Clean the Temporary Internet Files folder, which may contain infected files (How to clean Temporary Internet Files folder).
- Find and delete all copies of the worm's file together with "autorun.inf" scripts on removable drives.
- Reboot the computer.
*Manual removal may cause unexpected system behaviour and should be performed at your own risk.
