Worm.Win32.Dorkbot_431629407c
Gen:Variant.Symmi.24717 (BitDefender), Worm:Win32/Dorkbot.I (Microsoft), HEUR:Trojan.Win32.Generic (Kaspersky), Virus.Win32.Sality.at (v) (VIPRE), BackDoor.IRC.NgrBot.146 (DrWeb), Gen:Variant.Symmi.24717 (B) (Emsisoft), PWS-Zbot-FBDR!431629407C74 (McAfee), Worm.Win32.Dorkbot (Ikarus), Gen:Variant.Symmi.26708 (FSecure), BackDoor.Generic17.QDD (AVG), Win32:Sality (Avast), TROJ_GEN.R0CBC0DAD14 (TrendMicro), Backdoor.Win32.Farfli.FD, 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, Virus, 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: 431629407c74a6f4c8a2db4174fdf2c0
SHA1: 23dc535d2be04b15cbd0b3f13545ac7f0dddc46e
SHA256: 2871523068ea6be6277e7501c33be22fdc636e0ef89e9ecbb9c3d07654173f6c
SSDeep: 3072:QDnFwDAVcNUhSIhd2qzZQ2VGCemFb0x8vIH9qGs9Z1wF0kPPRNu6/Owkjz:QrDpMIqqzZQE1FbZvIH/0zkDu9VX
Size: 193536 bytes
File type: EXE
Platform: WIN32
Entropy: Packed
PEID: BorlandDelphi30, UPolyXv05_v6
Company: no certificate found
Created at: 2011-02-08 21:11:31
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:540
%original file name%.exe:332
The Worm injects its code into the following process(es):
mspaint.exe:240
File activity
The process mspaint.exe:240 makes changes in the file system.
The Worm creates and/or writes to the following file(s):
%Documents and Settings%\%current user%\Application Data\Microsoft\Pukmkb.exe (673 bytes)
The Worm deletes the following file(s):
C:\%original file name%.exe (0 bytes)
The process %original file name%.exe:332 makes changes in the 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 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 17 00 00 00 01 00 00 00 00 00 00 00"
[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "DD 04 9E 1F E9 C3 D3 4A D4 5E 49 1A 1E 62 B3 DD"
[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"
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]
"Pukmkb" = "%Documents and Settings%\%current user%\Application Data\Microsoft\Pukmkb.exe"
The Worm deletes the following value(s) in system registry:
[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"AutoConfigURL"
"ProxyServer"
"ProxyOverride"
The process %original file name%.exe:540 makes changes in the system registry.
The Worm creates and/or sets the following values in system registry:
[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "13 F2 13 C2 00 BF 26 BB 98 BE 99 6E C7 0C 0A 0A"
[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"AppData" = "%Documents and Settings%\%current user%\Application Data"
The process %original file name%.exe:332 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 16 00 00 00 01 00 00 00 00 00 00 00"
[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "8B 66 3A 86 95 7C 2F 73 95 81 84 AA C6 BF 51 24"
[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"
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"
"ProxyServer"
"ProxyOverride"
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 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 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:540
%original file name%.exe:332 - Delete the original Worm file.
- Delete or disinfect the following files created/modified by the Worm:
%Documents and Settings%\%current user%\Application Data\Microsoft\Pukmkb.exe (673 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) - Delete the following value(s) in the autorun key (How to Work with System Registry):
[HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
"Pukmkb" = "%Documents and Settings%\%current user%\Application Data\Microsoft\Pukmkb.exe"
[HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
"Screen Saver Pro 3.1" = "%Documents and Settings%\%current user%\Application Data\ScreenSaverPro.scr" - 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.
