Threat Monitor
Trojan-Downloader.Win32.Kido.a
| Aliases: | W32.Downadup.C ,Win32/Conficker.C ,W32/Confick-G ,Net-Worm.Win32.Kido |
|---|---|
| Pattern: | 200903180927 |
| Threat Type | Propagation Methods | Systems Affected | Risk Level |
|---|---|---|---|
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Technical details
This malicious program is a Windows DLL file.
Installation
The malware copies its executable file with random names to the following directories:
%Program Files%Windows Media Player<rnd>.dll
%Program Files%WindowsNT<rnd>.dll
%Program Files%Movie Maker<rnd>.dll
%SpecialFolder%<rnd>.dll
%System%<rnd>dir.dll
%Temp%<rnd>.dll
, <rnd> is a random string of symbols.
In order to ensure that the malware is launched automatically when the system is rebooted, the program registers its executable file in the system registry:
"<rnd>" = "rundll32.exe <path to Trojan file>"
<rnd> is a random string of symbols.
The malware also deletes the registry key show below in order to make it impossible to boot the system in safe mode:
It deletes the registry key shown below in order to disable Windows Security Center notifications:
ShellServiceObjects{FD6905CE-952F-41F1-9A6F-135D9C6622CC}]
It deletes the autorun parameter for Windows Defender:
It also modifies the following system registry key value by adding a link to the Trojan service:
"netsvcs" = "<original value><name of Trojan service>"
In order to ensure that the Trojan is launched next time the system is started, it creates a system service which launches the Trojan dll each time Windows is booted, creating the registry key shown below:
"Description" = "<description of a system service>"
"DisplayName" = "Manager Security"
"ImagePath" = REG_EXPAND_SZ, "%SystemRoot%system32svchost.exe -k netsvcs"
"Start" = "dword:0x00000002"
[HKLMSYSTEMCurrentControlSetServices<%;rnd%>Parameters]
"ServiceDll" = "%System%<%rnd>%.dll"
<rnd> is a random string of symbols.
The name of the service which is displayed is made up of words from the list below:
Policy Discovery Storage Power Logon Machine Browser Management Framework Component Trusted Backup Notify Audit Control Hardware Windows Update Universal Task Support Shell Security Network Monitor Microsoft Manager Installer Image Helper Driver Config Center Boot
The name of the service is made up of a combination of words from the list below:
Time System svc Svc srv Srv Service Server serv prov mon mgmt man logon auto agent access
It also includes a word from the list shown below:
xml wuau wsc Wmi Wmdm win W32 Trk Tapi Sec Remote Ras Ntms Net Lanman Ias help Event Audio App
The malware flags its presence in the system by creating a unique identifier as shown below:
Global%rnd%-7
Payload
The malware checks the current date; if this is later than 1st April 2009, the malware will deliver its payload.
The malware checks the system for the following directories:
Adobe Agent App Assemblies assembly Boot Build Calendar Collaboration Common Components Cursors Debug Defender Definitions Digital Distribution Documents Downloaded en Explorer Files Fonts Gallery Games Globalization Google Help IME inf Installer Intel Inter Internet Java Journal Kernel L2S Live Logs Mail Maker Media Microsoft Mobile Modem Movie MS msdownld NET New Office Offline Options Packages Pages Patch Performance Photo PLA Player Policy Prefetch Profiles Program Publish Reference Registered registration Reports Resources schemas Security Service Setup Shell Software Speech System Tasks Temp tmp tracing twain US Video Visual Web winsxs Works Zx
If these directories are not found, the Trojan will cease running.
When launched, depending on the specific modification of the malware, it disables some or all of the services listed below:
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)
In order to do this, it modifies the original Start value for each service to that shown below:
The Trojan injects its code in the address space of the system processes shown below:
explorer.exe (if injection into svchost.exe is not successful)
services.exe (for Windows 2000)
This code delivers the Trojan’s main malicious payload.
The Trojan does not use a driver to gain access to the network protocol as
the Kido worm did.
The Trojan hooks the following API calls (from dnsrslvr.dll) in order to block
access to listed user domains:
DNS_Query_UTF8
DNS_Query_W
Query_Main
sendto
NetpwPathCanonicalize
InternetGetConnectedState
It blocks access to sites and addresses which contain any of the strings listed below:
vet. sans. nai. msft. msdn. llnwd. llnw. kav. gmer. cert. ca. bit9. avp. avg. windowsupdate wilderssecurity virus virscan trojan trendmicro threatexpert threat technet symantec sunbelt spyware spamhaus sophos secureworks securecomputing safety.live rootkit rising removal quickheal ptsecurity prevx pctools panda onecare norton norman nod32 networkassociates mtc.sri msmvps msftncsi mirage microsoft mcafee malware kaspersky k7computing jotti ikarus hauri hacksoft hackerwatch grisoft gdata freeav free-av fortinet f-secure f-prot ewido etrust eset esafe emsisoft dslreports drweb Defender cyber-ta cpsecure conficker computerassociates comodo clamav centralcommand ccollomb castlecops bothunter avira avgate avast arcabit antivir anti- ahnlab agnitum
It terminates all processes that contain one of the strings listed below in their names:
wireshark unlocker tcpview sysclean scct_ regmon procmon procexp ms08-06 mrtstub mrt. mbsa. klwk kido kb958 kb890 hotfix gmer filemon downad confick avenger autoruns
By doing this, the Trojan prevents access to the majority of sites which offer antivirus database updates or dedicated utilities to remove the malicious program.
The Trojan checks for a connection to the sites shown below:
netlog.com yandex.ru zedo.com doubleclick.com 2ch.net allegro.pl hi5.com seznam.cz ebay.com odnoklassniki.ru myspace.com go.com yahoo.com fastclick.com sourceforge.net comcast.net wikimedia.org miniclip.com mininova.org facebook.com adultadworld.com 4shared.com skyrock.com biglobe.ne.jp download.com youporn.com adultfriendfinder.com nicovideo.jp rambler.ru foxnews.com terra.com.br zshare.net bigpoint.com yahoo.co.jp dell.com ziddu.com livejournal.com mixi.jp rediff.com youtube.com mywebsearch.com tube8.com xhamster.com naver.com tribalfusion.com narod.ru hyves.nl xiaonei.com clicksor.com adsrevenue.net mail.ru files.wordpress.com tinypic.com ebay.it digg.com linkbucks.com imdb.com tagged.com nba.com msn.com blogfa.com recvfrom livedoor.com linkedin.com kaixin001.com reference.com megaporn.com torrentz.com orange.fr geocities.com pcpop.com paypopup.com fc2.com partypoker.com ask.com googlesyndication.com badongo.com goo.ne.jp aweber.com answers.com espn.go.com seesaa.net metroflog.com aim.com megaclick.com metacafe.com netflix.com sonico.com photobucket.com awempire.com depositfiles.com imageshack.us gougou.com pornhub.com mediafire.com typepad.com imeem.com perfspot.com 56.com soso.com ameba.jp friendster.com google.com tuenti.com imagevenue.com taringa.net badoo.com disney.go.com livejasmin.com multiply.com ucoz.ru flickr.com mapquest.com ameblo.jp pogo.com apple.com cricinfo.com ebay.co.uk studiverzeichnis.com vkontakte.ru wordpress.com rapidshare.com wikimedia.org icq.com xnxx.com veoh.com ning.com pconline.com.cn tudou.com sakura.ne.jp fotolog.net bbc.co.uk conduit.com vnexpress.net ebay.de craigslist.org live.com xvideos.com ioctlsocket tianya.cn alice.it bebo.com verizon.net megaupload.com kooora.com thepiratebay.org
Main functionality
The Trojan downloads files from URLs 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 algorithm used to generate domain names uses Microsoft Base Cryptographic Provider v1.0 in order to generate pseudorandom values.
Domains are chosen from the list below:
vn vc us tw to tn tl tj tc su sk sh sg sc ru ro ps pl pk pe no nl nf my mw mu ms mn me md ly lv lu li lc la kz kn is ir in im ie hu ht hn hk gy gs gr gd fr fm es ec dm dk dj cz cx cn cl ch cd ca bz bo be at as am ag ae ac com.ve com.uy com.ua com.tw com.tt com.tr com.sv com.py com.pt com.pr com.pe com.pa com.ni com.ng com.mx com.mt com.lc com.ki com.jm com.hn com.gt com.gl com.gh com.fj com.do com.co com.bs com.br com.bo com.ar com.ai com.ag co.za co.vi co.uk co.ug co.nz co.kr co.ke co.il co.id co.cr
The new modification of the Trojan generates 50000 domain names per 24 hours, skipping the address groups listed below:
127.x.x.x 169.254.x.x x.198.x.x x.255.255.253 224-239.x.x.x 240-255.x.x.x
The Trojan chooses 500 domain names at random from the list generated and attempts to connect to them in order to download files. If the connection attempt is not successful, after a short interval another 500 names will be chosen.
The body of the Trojan also contains a blacklist of 399 IP addresses which belong to security companies.
The Trojan gets the current date from one of the sites shown below:
http://www.ask.com
http://www.yahoo.com
http://www.google.com
http://www.baidu.com
http://www.rapidshare.com
http://www.imageshack.us
http://www.facebook.com
If a connection cannot be established to these sites, the current system date will be used.
Downloaded files are saved as follows:
<rnd> is a random string of symbols.
Removal instructions
If your computer does not have an up-to-date antivirus, or does not have an antivirus solution at all, follow the instructions below to delete the malicious program:
- Delete the following system
registry key:
[HKLMSYSTEMCurrentControlSetServices<%;rnd%>]
- Delete “%System%<rnd>.dll” from the system registry key
value shown below:
[HKLMSOFTWAREMicrosoftWindows NTCurrentVersionSvcHost] "netsvcs"
- Restore the following registry keys:
[HKLM SYSTEMCurrentControlSetControlSafeBoot]
[HKLMSoftwareMicrosoftWindowsCurrentVersionexplorerShellServiceObjects
{FD6905CE-952F-41F1-9A6F-135D9C6622CC}]
[HKLMSoftwareMicrosoftWindowsCurrentVersionRunWindows Defender] - Reboot the computer.
- Delete the following files:
%Program Files%Internet Explorer<rnd>.dll
%Program Files%Windows Media Player<rnd>.dll
%Program Files%WindowsNT<rnd>.dll
%Program Files%Movie Maker<rnd>.dll
%SpecialFolder%<rnd>.dll
%System%<rnd>dir.dll
%Temp%<rnd>.dll - Restore the launch of the following services:
wscsvc - Security Center
wuauserv - Automatic updates
BITS - Background Intelligent Transfer Service
WinDefend - Windows Defender
ERSvc - Error Reporting Service
WerSvc - Windows Error Reporting Service - Update your antivirus databases and perform a full scan of the computer .


