Worm.Win32.Dorkbot_64f19f18e0

by malwarelabrobot on January 3rd, 2014 in Malware Descriptions.

HEUR:Trojan.Win32.Generic (Kaspersky), Worm.Win32.Dorkbot (VIPRE), Backdoor.Win32.Ruskill!IK (Emsisoft), Backdoor.Win32.Farfli.FD, Worm.Win32.Dorkbot.FD, mzpefinder_pcap_file.YR, WormDorkbot.YR, GenericUDPFlooder.YR, GenericIRCBot.YR, GenericMSNWorm.YR, GenericUSBInfector.YR, GenericDNSBlocker.YR, GenericDownloader.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: 64f19f18e052d7aa386e21999cbfdc7f
SHA1: 4de16358a6f6e5fdab549ccba3f0b55f50c26394
SHA256: f81b85c0f101dd0bc0917c448bd849f4a77a93b45c8e925c58d81d5c001bf993
SSDeep: 3072:7nU1yQ9fIR7c0Y66MSnWDue VNg23zO89Rb:TU79kc0AMSWDue VmrSB
Size: 126976 bytes
File type: EXE
Platform: WIN32
Entropy: Packed
PEID: MicrosoftVisualC, MicrosoftVisualCv50v60MFC, MicrosoftVisualC50, UPolyXv05_v6, Armadillov171
Company: no certificate found
Created at: 2011-09-22 15:12:53
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:916
1.tmp:844
1.tmp:1796
Xtkmkj.exe:844

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

calc.exe:1064
notepad.exe:1072
charmap.exe:1536

File activity

The process calc.exe:1064 makes changes in the file system.
The Worm creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\Local Settings\Temp\c731200 (9 bytes)

The process notepad.exe:1072 makes changes in the file system.
The Worm creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\Application Data\Identities\Uukmkg.exe (601 bytes)

The Worm deletes the following file(s):

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

The process %original file name%.exe:916 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 (601 bytes)

The process 1.tmp:844 makes changes in the file system.
The Worm creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\Application Data\c731200 (601 bytes)

Registry activity

The process calc.exe:1064 makes changes in the system registry.
The Worm creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "E5 04 B9 80 03 27 6C 90 9C BF 97 9C 1E E8 94 1E"

The process notepad.exe:1072 makes changes in the 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"
"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"

"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 14 00 00 00 01 00 00 00 00 00 00 00"

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "51 4E DD A9 34 CC 2B AE 6A BB A3 53 9E 00 15 79"

[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:

"ProxyBypass" = "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]
"Uukmkg" = "%Documents and Settings%\%current user%\Application Data\Identities\Uukmkg.exe"

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"
"ProxyServer"
"ProxyOverride"

The process charmap.exe:1536 makes changes in the system registry.
The Worm creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "3B 66 DD DB CF 55 17 F5 64 9B BC 87 58 66 FF 6C"

The process %original file name%.exe:916 makes changes in the system registry.
The Worm creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "8F EC 22 39 BD 9F 90 1E 8A F4 13 AF C2 D9 E7 4C"

[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 1.tmp:844 makes changes in the system registry.
The Worm creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "D0 67 39 38 BE C0 92 A1 32 86 68 76 82 78 9F CD"

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

The process 1.tmp:1796 makes changes in the system registry.
The Worm creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "11 1A 9E 3D 7B 51 5C 65 F8 56 13 89 E9 D9 F2 1E"

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

The process Xtkmkj.exe:844 makes changes in the system registry.
The Worm creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "71 BC 1D 92 E6 A2 46 B0 B1 01 FE 99 A0 EC 08 C5"

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

Network activity (URLs)

URL IP
hxxp://196.196.8.53/6542.exe (ET POLICY PE EXE or DLL Windows file download , Malicious)
ng.lighthousez11.com 222.88.194.178
ng.themarketbaby.com Unresolvable
ng.grasshopperz11.com Unresolvable


HOSTS file anomalies

No changes have been detected.

Rootkit activity

The Worm installs the following user-mode hooks in dnsapi.dll:

DnsQuery_A
DnsQuery_W

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:916
    1.tmp:844
    1.tmp:1796
    Xtkmkj.exe:844

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

    %Documents and Settings%\%current user%\Local Settings\Temp\c731200 (9 bytes)
    %Documents and Settings%\%current user%\Application Data\Identities\Uukmkg.exe (601 bytes)
    %Documents and Settings%\%current user%\Application Data\Xtkmkj.exe (601 bytes)
    %Documents and Settings%\%current user%\Application Data\c731200 (601 bytes)

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

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

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

  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.