Worm.Win32.Dorkbot_04d32029a7

by malwarelabrobot on January 24th, 2014 in Malware Descriptions.

HEUR:Trojan.Win32.Generic (Kaspersky), Trojan.Win32.Servlice.a (v) (VIPRE), Trojan.Win32.Servlice!IK (Emsisoft), Worm.Win32.Dorkbot.FD, WormDorkbot.YR, GenericUDPFlooder.YR, GenericIRCBot.YR, GenericMSNWorm.YR, GenericUSBInfector.YR, GenericDNSBlocker.YR, GenericAutorunWorm.YR, GenericSYNFlooder.YR, Blazebot.YR, GenericInjector.YR, BankerGeneric.YR, GenericProxy.YR, GenericPhysicalDrive0.YR (Lavasoft MAS)
Behaviour: Banker, Trojan, 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: 04d32029a7e277222a5c48c432b23b26
SHA1: 79d913d422cbde60ddaae8cfa9d6e865774e8af4
SHA256: 4788e5dba7cbdc72e68e10a67b3394443f133b1263b3f7ef30e537b8979513dd
SSDeep: 6144:/DVpEvBTe/muyUxGUMj7dZJ02E14Ur7QYBEdDi0fz:hpItepyUUUMj7dfUQGEdDBz
Size: 262736 bytes
File type: EXE
Platform: WIN32
Entropy: Packed
PEID: UPolyXv05_v6
Company: QuickSet
Created at: 2013-07-07 04:05:17
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:464
msn.exe:240
msn.exe:1368
7.exe:920

The Worm injects its code into the following process(es):
No processes have been created.

File activity

The process msn.exe:240 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\aut8.tmp (1137 bytes)
%Documents and Settings%\%current user%\N61Q11.FF6 (601 bytes)

The Worm deletes the following file(s):

%Documents and Settings%\%current user%\Local Settings\Temp\aut8.tmp (0 bytes)
%Documents and Settings%\%current user%\N61Q11.FF6 (0 bytes)

The process msn.exe:1368 makes changes in the file system.
The Worm creates and/or writes to the following file(s):

%WinDir%\csrss.exe (5441 bytes)
%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\desktop.ini (67 bytes)

The process 7.exe:920 makes changes in the file system.
The Worm creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\Y44D\msn.exe (9665 bytes)

The Worm deletes the following file(s):

%Documents and Settings%\%current user%\Y44D\__tmp_rar_sfx_access_check_1260687 (0 bytes)

Registry activity

The process %original file name%.exe:464 makes changes in the system registry.
The Worm creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "D6 26 4D F7 C3 FE 9D B1 6A E0 C4 3B 6B DA 3D 7B"

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

The process msn.exe:240 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 80 40 41 4A CB DA 7D 9A 71 1B 13 D6 D3 A4 0E"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd73-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd72-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{b98117e8-75ca-11e2-81b2-000c293708fb}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd75-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

The process msn.exe:1368 makes changes in the system registry.
The Worm creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "C4 63 A5 00 52 B3 BE 89 54 06 F1 6D 3B 66 65 1F"

[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\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"

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

[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]
"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\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"

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

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

To automatically run itself each time Windows is booted, the Worm adds the following link to its file to the system registry autorun key:

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
"Remote Registry Service" = "csrss.exe"

The process 7.exe:920 makes changes in the system registry.
The Worm creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "9E 46 67 60 54 6F DB 4F 5B DC 71 35 56 A2 C5 38"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd73-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

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

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

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

[HKCU\Software\Microsoft\Windows\ShellNoRoam\MUICache\%Documents and Settings%\%current user%\Y44D]
"msn.exe" = "msn"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd72-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{b98117e8-75ca-11e2-81b2-000c293708fb}]
"BaseClass" = "Drive"

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

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

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd75-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

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

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 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:

"UNCAsIntranet" = "1"

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

"ProxyBypass" = "1"

Network activity (URLs)

URL IP
hxxp://www.whatismyip.com/ (ET POLICY Internal Host Retrieving External IP via whatismyip.com - Possible Infection ) 141.101.120.15
hxxp://checkip.dyndns.com/ (ET POLICY DynDNS CheckIp External IP Address Server Response )
vids.p0rn-lover.us 82.145.57.209
checkip.dyndns.org 216.146.38.70


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

  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:464
    msn.exe:240
    msn.exe:1368
    7.exe:920

  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\aut8.tmp (1137 bytes)
    %Documents and Settings%\%current user%\N61Q11.FF6 (601 bytes)
    %WinDir%\csrss.exe (5441 bytes)
    %Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\desktop.ini (67 bytes)
    %Documents and Settings%\%current user%\Y44D\msn.exe (9665 bytes)

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

    [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
    "Remote Registry Service" = "csrss.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.