Worm.Win32.Dorkbot_40ab03073f

by malwarelabrobot on December 10th, 2013 in Malware Descriptions.

Trojan.Win32.ShipUp.aak (Kaspersky), Trojan.Win32.Scar.egqm (v) (VIPRE), Backdoor.Win32.Ruskill!IK (Emsisoft), 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, Backdoor, Flooder, Worm, 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.

Summary
Technical Details
Removal Recommendations

MD5: 40ab03073f415e78bf2ca975a4329418
SHA1: 92c65099ffb6b6df43b69f6679887ce2899f413b
SHA256: ea7f0f184fc7c307242f1562282262a85425434b19204c0050e1821d187b51ca
SSDeep: 3072:uM16ScB62gsvQ6zTm3Gs/4OU89kHpsDxb3tHCAYoKAOp:uMRWdgsvQ6zHs/4y9kHps9ZEb
Size: 139264 bytes
File type: EXE
Platform: WIN32
Entropy: Packed
PEID: Armadillov171, MicrosoftVisualC, MicrosoftVisualCv50v60MFC, MicrosoftVisualC50, UPolyXv05_v6
Company: no certificate found
Created at: 2011-07-14 19:38:34


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:1784
Xtkmkj.exe:1728

File activity

The process %original file name%.exe:1784 makes changes in the file system.
The Worm creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\Application Data\Xtkmkj.exe (673 bytes)

Registry activity

The process %original file name%.exe:1784 makes changes in the system registry.
The Worm creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "DD F9 AF 17 04 56 E4 39 5B F0 EA 40 90 88 4F D4"

[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]
"Xtkmkj" = "%Documents and Settings%\%current user%\Application Data\Xtkmkj.exe"

The process Xtkmkj.exe:1728 makes changes in the system registry.
The Worm creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "0C A6 B5 96 96 57 C5 E5 B0 9A 61 A4 BF 94 CD 89"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"AppData" = "%Documents and Settings%\%current user%\Application Data"

Network activity (URLs)

No activity has been detected.

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
GetAddrInfoW

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

  1. Click (here) to download and install Ad-Aware Free Antivirus.
  2. Update the definition files.
  3. Run a full scan of your computer.


Manual removal*

  1. Scan a system with an anti-rootkit tool.
  2. Terminate malicious process(es) (How to End a Process With the Task Manager):

    %original file name%.exe:1784
    Xtkmkj.exe:1728

  3. Delete the original Worm file.
  4. Delete or disinfect the following files created/modified by the Worm:

    %Documents and Settings%\%current user%\Application Data\Xtkmkj.exe (673 bytes)

  5. Delete the following value(s) in the autorun key (How to Work with System Registry):

    [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
    "Xtkmkj" = "%Documents and Settings%\%current user%\Application Data\Xtkmkj.exe"

  6. Find and delete all copies of the worm's file together with "autorun.inf" scripts on removable drives.
  7. Reboot the computer.

*Manual removal may cause unexpected system behaviour and should be performed at your own risk.