Worm.Win32.Dorkbot_0c8ecb8adc

by malwarelabrobot on July 4th, 2013 in Malware Descriptions.

HEUR:Trojan.Win32.Generic (Kaspersky), Trojan.Win32.Zbot.fdm (v) (VIPRE), Trojan-Spy.Win32.Zbot!IK (Emsisoft), Backdoor.Win32.Farfli.FD, Worm.Win32.Dorkbot.FD, BankerGeneric.YR, GenericInjector.YR, GenericPhysicalDrive0.YR, WormDorkbot.YR, GenericAutorunWorm.YR, GenericIRCBot.YR, GenericDNSBlocker.YR, GenericUDPFlooder.YR, GenericSYNFlooder.YR, GenericProxy.YR, GenericUSBInfector.YR, GenericMSNWorm.YR (Lavasoft MAS)
Behaviour: Trojan-Spy, 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: 0c8ecb8adc7f5a7fc6eeaae5c82a132d
SHA1: b90fc7b3051e20ea5263ec4cbcd215f92e8cb008
SHA256: 8b2e715184dd62e48492d650785f8a3e8a7e710d50c540ba9c1473724fe7620a
SSDeep: 3072:OyPcKnMctaFQvDp wHWVYp lk8G4M6ozDfXBqv9o/fqmJY5fUCgkwv:LPrMc0SLpjHWVYp 68G4kz7x Sfq8afi
Size: 149504 bytes
File type: PE32
Platform: WIN32
Entropy: Packed
PEID: BorlandDelphi30; UPolyXv05_v6
Company: no certificate found
Created at: 2005-07-27 18:39:29


Summary:

Trojan-Spy. Spy program intended for stealing user's confidential data.
Banker. Steals data relating to online banking systems, e-payment systems and credit card systems.
Backdoor. Malware that enables a remote control of victim's machine.
WormAutorun. A worm spreads 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 communicates with command and control servers via IRC channel.
MSNWorm. A worm spreads its copies through the MSN Messanger.
DNSBlocker. A program blocks 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 registers 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):

0c8ecb8adc7f5a7fc6eeaae5c82a132d.exe:540
0c8ecb8adc7f5a7fc6eeaae5c82a132d.exe:1376

The Worm injects its code into the following process(es):

mspaint.exe:240

File activity

The process mspaint.exe:240 makes changes in a file system.
The Worm creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\Application Data\Microsoft\Nukmkz.exe (673 bytes)
%Documents and Settings%\%current user%\Application Data\1.exe (167 bytes)

The Worm deletes the following file(s):

C:\0c8ecb8adc7f5a7fc6eeaae5c82a132d.exe (0 bytes)
%Documents and Settings%\%current user%\Application Data\1.tmp (0 bytes)

The process 0c8ecb8adc7f5a7fc6eeaae5c82a132d.exe:1376 makes changes in a file system.
The Worm creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\Application Data\ScreenSaverPro.scr (673 bytes)
%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\desktop.ini (67 bytes)
%Documents and Settings%\%current user%\Application Data\temp.bin (673 bytes)

Registry activity

The process mspaint.exe:240 makes changes in a system registry.
The Worm creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths]
"Directory" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path4]
"CacheLimit" = "65452"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path4]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache4"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path2]
"CacheLimit" = "65452"

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

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

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path2]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache2"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Common AppData" = "%Documents and Settings%\All Users\Application Data"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Cache" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files"

[HKLM\System\CurrentControlSet\Hardware Profiles\0001\Software\Microsoft\windows\CurrentVersion\Internet Settings]
"ProxyEnable" = "0"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path1]
"CacheLimit" = "65452"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Connections]
"SavedLegacySettings" = "3C 00 00 00 17 00 00 00 01 00 00 00 00 00 00 00"

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "AF 4D 9E F5 74 13 CB 83 38 D5 FA 59 9A 2C 30 8A"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path1]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache1"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path3]
"CacheLimit" = "65452"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"MigrateProxy" = "1"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"History" = "%Documents and Settings%\%current user%\Local Settings\History"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path3]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache3"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths]
"Paths" = "4"

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]
"Nukmkz" = "%Documents and Settings%\%current user%\Application Data\Microsoft\Nukmkz.exe"

The Worm modifies IE settings for security zones to map all local web-nodes with no dots which do not refer to any zone to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"UNCAsIntranet" = "1"

The Worm modifies IE settings for security zones to map all web-nodes that bypassing proxy to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"ProxyBypass" = "1"

Proxy settings are disabled:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"ProxyEnable" = "0"

The Worm modifies IE settings for security zones to map all urls to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"IntranetName" = "1"

The Worm deletes the following value(s) in system registry:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"AutoConfigURL"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"ProxyServer"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"ProxyOverride"

The process 0c8ecb8adc7f5a7fc6eeaae5c82a132d.exe:540 makes changes in a system registry.
The Worm creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "11 56 EA 67 8B 0F 7E 12 AE D5 45 B8 96 B6 F6 E0"

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

The process 0c8ecb8adc7f5a7fc6eeaae5c82a132d.exe:1376 makes changes in a system registry.
The Worm creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths]
"Directory" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path4]
"CacheLimit" = "65452"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path4]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache4"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path2]
"CacheLimit" = "65452"

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

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

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path2]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache2"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Common AppData" = "%Documents and Settings%\All Users\Application Data"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Cache" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files"

[HKLM\System\CurrentControlSet\Hardware Profiles\0001\Software\Microsoft\windows\CurrentVersion\Internet Settings]
"ProxyEnable" = "0"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path1]
"CacheLimit" = "65452"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Connections]
"SavedLegacySettings" = "3C 00 00 00 16 00 00 00 01 00 00 00 00 00 00 00"

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "48 3D B7 B5 9C D3 C4 57 7D 3D 88 BD 71 CE 7B 62"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path1]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache1"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path3]
"CacheLimit" = "65452"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"MigrateProxy" = "1"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"History" = "%Documents and Settings%\%current user%\Local Settings\History"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path3]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache3"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths]
"Paths" = "4"

The Worm modifies IE settings for security zones to map all local web-nodes with no dots which do not refer to any zone to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"UNCAsIntranet" = "1"

The Worm modifies IE settings for security zones to map all web-nodes that bypassing proxy to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"ProxyBypass" = "1"

Proxy settings are disabled:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"ProxyEnable" = "0"

The Worm modifies IE settings for security zones to map all urls to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"IntranetName" = "1"

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]
"Screen Saver Pro 3.1" = "%Documents and Settings%\%current user%\Application Data\ScreenSaverPro.scr"

The Worm deletes the following value(s) in system registry:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"AutoConfigURL"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"ProxyServer"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"ProxyOverride"

Network activity (URLs)

A bot communicates with command and control servers via IRC channel.
This program can launch a proxy server (SOCKS4) on a designated TCP port.
A program blocks designated DNS servers for making it difficult for users to locate specific domains or web sites on the Internet.
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.
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.

URL: hxxp://54.218.44.125/6516.exe Country: United States Verdict: Malicious
URL: t.laeranat1.com IP: 59.51.114.85

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 dnsapi.dll:

DnsQuery_A
DnsQuery_W

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 spreads 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 registers 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 spreads 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):

    0c8ecb8adc7f5a7fc6eeaae5c82a132d.exe:540
    0c8ecb8adc7f5a7fc6eeaae5c82a132d.exe:1376

  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\Microsoft\Nukmkz.exe (673 bytes)
    %Documents and Settings%\%current user%\Application Data\1.exe (167 bytes)
    %Documents and Settings%\%current user%\Application Data\ScreenSaverPro.scr (673 bytes)
    %Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\desktop.ini (67 bytes)
    %Documents and Settings%\%current user%\Application Data\temp.bin (673 bytes)

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

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

    [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
    "Screen Saver Pro 3.1" = "%Documents and Settings%\%current user%\Application Data\ScreenSaverPro.scr"

  6. Clean the Temporary Internet Files folder, which may contain infected files (How to clean Temporary Internet Files folder).
  7. Find and delete all copies of the worm's file together with "autorun.inf" scripts on removable drives.
  8. Reboot the computer.

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