| Technical details |
This malicious program exploits the MS08-067 vulnerability to spread via network resources and removable storage media.
This modification of the worm is a Windows PE DLL file. The file is 158110 bytes in size. It is packed using UPX.
Installation
The worm copies its executable file with random names to the following directories:
%System%\dir.dll
%Program Files%\Internet Explorer\.dll
%Program Files%\Movie Maker\.dll
%All Users Application Data%\.dll
%Temp%\.dll
%System%\tmp
%Temp%\.tmp In order to ensure that the worm is launched next time the system is started, it creates a system service which launches the worm’s executable file each time Windows is booted. The following registry key will be created:
The name of the service will be created from combining words from the list below:
Boot
Center
Config
Driver
Helper
Image
Installer
Manager
Microsoft
Monitor
Network
Security
Server
Shell
Support
System
Task
Time
Universal
Update
Windows The worm also modifies the following system registry key value:
The worm hides its files in Explorer by modifying the registry key value shown below:
"Hidden" = "dword: 0x00000002"
"SuperHidden" = "dword: 0x00000000"
[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL]
"CheckedValue" = "dword: 0x00000000"
The worm flags its presence in the system by creating the unique identifier shown below:
Propagation
In order to spread quickly via networks, the worm uses tcpip.sys functions to increase the number of potential network connections.
The worm connects to the servers shown below in order to determine the external IP address of the victim machine:
http://www.getmyip.org
http://www.whatsmyipaddress.com
http://www.whatismyip.org
http://checkip.dyndns.org The worm then launches an HTTP server on a random TCP port; this is then used to download the worm's executable file to other computers.
Copies of the worm have the extensions listed below:
.bmp
.gif
.jpeg
.png The worm gets the IP addresses of computers in the same network as the victim machine and attacks them via a buffer overrun vulnerability (MS08-067) in the Server service. More details about the vulnerability can be found here: www.microsoft.com/technet/security/Bulletin/MS08-067.mspx. The worm sends a specially crafted RPC request to TCP ports 139 (NetBIOS) and 445 (Direct hosted SMB) remote machines on remote machines. This causes a buffer overrun when the wcscpy_s function is called in netapi32.dll, which launches code that downloads the worm's executable file to the victim machine and launches it. The worm is then installed on the new victim machine.
The worm then hooks the NetpwPathCanonicalize API call (netapi.dll) to prevent buffer overruns caused by the absence of a check on the size of outgoing strings. By doing this, the worm makes repeat exploitation of the vulnerability impossible.
In order to speed up propagation, the worm modifies the following registry value:
"TcpNumConnections" = "dword:0x00FFFFFE"
In order to exploit the vulnerability described above, the worm attempts to connect to the Administrator account on the remote machine. It searches the network for an appropriate machine and gets a list of users. It then attempts to brute force each user account using the passwords shown below:z
99999999 | 11111111 | unknown | password123 |
In order to gain administrator access, the worm copies itself to the following shared folders:
\\
The worm can then be launched remotely or scheduled for remote launch using the following commands:
Spreading via removable storage media
The worm copies its executable file to all removable media under the following name:
%d%>-%d%>\
is the disk
In addition to its executable file, the worm also places the file shown below in the root of every disk:
This file will launch the worm's executable file each time Explorer is used to open the infected disk.
| Payload |
When launching, the worm injects its code into the address space of one of the “svchost.exe” system processes. (The worm may also write its code to the “explorer.exe” and “services.exe” processes.) This code delivers the worm's main malicious payload and:
- disables the following services:
Windows Automatic Update Service (wuauserv)
Background Intelligent Transfer Service (BITS)
Windows Security Center Service (wscsvc)
Windows Defender Service (WinDefend, WinDefender)
Windows Error Reporting Service (ERSvc)
Windows Error Reporting Service (WerSvc) - blocks access to addresses which contain any of the strings listed below:
nai
ca
avp
avg
vet
bit9
sans
cert
windowsupdate
wilderssecurity
threatexpert
castlecops
spamhaus
cpsecure
arcabit
emsisoft
sunbelt
securecomputing
rising
prevx
pctools
norman
k7computing
ikarus
hauri
hacksoft
gdata
fortinet
ewido
clamav
comodo
quickheal
avira
avast
esafe
ahnlab
centralcommand
drweb
grisoft
eset
nod32
f-prot
jotti
kaspersky
f-secure
computerassociates
networkassociates
etrust
panda
sophos
trendmicro
mcafee
norton
symantec
microsoft
defender
rootkit
malware
spyware
virus
In Windows Vista, the worm will disable autoconfiguration of the TCP/IP stack in order to speed up propagation via network channels by using a fixed window size for TCP packets:
The worm also hooks the following API calls (dnsrslvr.dll) in order to block access to the list of user domains:
DNS_Query_A
DNS_Query_UTF8
DNS_Query_W
Query_Main
sendto The worm may also download files from links of the type shown below:
rnd2 is a random number; URL is a link generated by a special algorithm which uses the current date. The worm gets the current date from one of the sites shown below:
http://www.w3.org
http://www.ask.com
http://www.msn.com
http://www.yahoo.com
http://www.google.com
http://www.baidu.com
http://www.myspace.com
http://www.msn.com
http://www.ebay.com
http://www.cnn.com
http://www.aol.com Downloaded files are saved to the Windows system directory under their original names.
| Removal instructions |
If your computer does not have an up-to-date antivirus solution, or does not have an antivirus solution at all, you can either use a special removal tool (which can be found here or follow the instructions below:
http://www.kaspersky.ru/support/wks6mp3/error?qid=208636215
Or follow the instructions below:
- Delete the following system registrykey: [HKLM\SYSTEM\CurrentControlSet\Services\netsvcs]
- Delete “%System%\
.dll” from the system registry key value shown below: [HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SvcHost]
"netsvcs" - Revert the following registry key values: [HKCR\ Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced]
"Hidden" = "dword: 0x00000002"
"SuperHidden" = "dword: 0x00000000"to
[HKCR\ Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced]
"Hidden" = "dword: 0x00000001"
"SuperHidden" = "dword: 0x00000001"[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL]
"CheckedValue" = "dword: 0x00000000"to
[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL]
"CheckedValue" = "dword: 0x00000001" - Reboot the computer.
- Delete the original worm file (the location will depend on how the program originally penetrated the victim machine).
- Delete copies of the worm:
%System%\dir.dll
%Program Files%\Internet Explorer\.dll
%All Users Application Data%\.dll
%Temp%\.dll
%System%\tmp
%Temp%\.tmp is a random string of symbols. - Delete the files shown below from all removable storage media:
:\autorun.inf :\RECYCLER\S-<%d%>-<%d%>-%d%>-%d%>-%d%>-%d%>-
%d%>\.vmx, - Download and install updates for the operating system: http://www.microsoft.com/technet/security/Bulletin/MS08-067.mspx
- Update your antivirus databases and perform a full scan of the computer (download a trial version of Kaspersky Anti-Virus).
- Or download f-secure here:
Update released: Jan 06 2009 22:05 GMT
Description Added: Jan 21 2009
Source: http://www.viruslist.com
