WORM_DORKBOT.XXSR
Worm:Win32/Dorkbot.I (Microsoft)
Windows
Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This worm monitors the Internet activities of the infected system to steal user credentials if the user visits websites with certain strings. It attempts to steal user credentials used in the certain websites. It monitors certain browsers. It has backdoor capabilities. It modifies the following system files. It hooks the following API to hide itself and to aid its routines.
It drops shortcut files pointing to the copy of itself in removable drives. These dropped .LNK files use the names of the folders located on the said drives for their file names. It then sets the attributes of the original folders to Hidden to trick the user into clicking the .LNK files.
This worm deletes the initially executed copy of itself.
TECHNICAL DETAILS
Arrival Details
This malware arrives via the following means:
- It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
- It arrives via removable drives.
- It may arrive through accessing malicious IFRAME tags inserted in HTML pages.
- It arrives via Instant Messaging and Social Networking sites
Installation
This worm drops the following copies of itself into the affected system:
- %Application Data%\Microsoft\Windows\Themes\{random filename}.exe
- %Application Data%\WindowsUpdate\Updater.exe
- %Application Data%\Update\Explorer.exe
- %Application Data%\Update\Update.exe
- %Application Data%\c731200
(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)
It drops the following component file(s):
- %User Temp%\c731200
(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Windows Update Installer = "%Application Data%\WindowsUpdate\Updater.exe"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random filename} = "%Application Data%\Microsoft\Windows\Themes\{random filename}.exe"
Other System Modifications
This worm modifies the following file(s):
- ipconfig.exe
- verclsid.exe
- regedit.exe
- rundll32.exe
- cmd.exe
- regsvr32.exe
Propagation
This worm drops the following copy(ies) of itself in all removable drives:
- {removable drive letter}:\{random filename}.exe
Other Details
This worm connects to the following URL(s) to get the affected system's IP address:
- api.wipmania.com
It connects to the following possibly malicious URL:
- {BLOCKED}.{BLOCKED}.28.199:3720
- n.{BLOCKED}s.ru
- n.{BLOCKED}duhz.ru
- n.{BLOCKED}lgoja.ru
- n.{BLOCKED}xxbf.ru
- n.{BLOCKED}lho.ru
- n.{BLOCKED}gcj.ru
- n.{BLOCKED}rap.ru
- n.{BLOCKED}pku.ru
- n.{BLOCKED}ntif.ru
- n.{BLOCKED}snc.ru
- n.{BLOCKED}yxd.ru
- n.{BLOCKED}wh.ru
- n.{BLOCKED}wqk.ru
- n.{BLOCKED}kpaz.ru
- n.{BLOCKED}kcb.ru
- n.{BLOCKED}khvl.ru
- n.{BLOCKED}anm.ru
- n.{BLOCKED}xwfa.ru
- n.{BLOCKED}gvly.ru
- n.{BLOCKED}zdu.ru
- n.{BLOCKED}otb.ru
- n.{BLOCKED}jxl.ru
- n.{BLOCKED}rii.ru
- n.{BLOCKED}qwk.ru
- n.{BLOCKED}nod.ru
- n.{BLOCKED}hum.ru
- n.{BLOCKED}aj.ru
- n.{BLOCKED}fvk.ru
- n.{BLOCKED}vqt.ru
- n.{BLOCKED}is.ru
- n.{BLOCKED}fxht.ru
- n.{BLOCKED}uve.ru
- n.{BLOCKED}rbj.ru
- n.{BLOCKED}lcr.ru
- n.{BLOCKED}zu.ru
- n.{BLOCKED}jzkq.ru
- n.{BLOCKED}lks.ru
- n.{BLOCKED}ijv.ru
- n.{BLOCKED}ihg.ru
- n.{BLOCKED}tli.ru
- n.{BLOCKED}tul.ru
- n.{BLOCKED}ii.ru
- n.{BLOCKED}xbi.ru
- n.{BLOCKED}be.ru
- n.{BLOCKED}ntle.ru
- n.{BLOCKED}nmk.ru
- n.{BLOCKED}qiv.ru
- n.{BLOCKED}lhsc.ru
- n.{BLOCKED}rqr.ru
- n.{BLOCKED}mbpd.ru
- n.{BLOCKED}dqe.ru
- n.{BLOCKED}bcw.ru
- n.{BLOCKED}tsx.ru
- n.{BLOCKED}zra.ru
- n.{BLOCKED}kkqj.ru
- n.{BLOCKED}ruc.ru
- n.{BLOCKED}dgz.ru
- n.{BLOCKED}lhx.ru
- n.{BLOCKED}djz.ru
- n.{BLOCKED}um.ru
- n.{BLOCKED}ryz.ru
- n.{BLOCKED}qoe.ru
- n.{BLOCKED}zun.ru
- n.{BLOCKED}qxi.ru
- n.{BLOCKED}ket.ru
- n.{BLOCKED}xsl.ru
- n.{BLOCKED}jysh.ru
- n.{BLOCKED}rnt.ru
- n.{BLOCKED}ajd.ru
- n.{BLOCKED}cxj.ru
- n.{BLOCKED}ufr.ru
- n.{BLOCKED}gfj.ru
- n.{BLOCKED}sy.ru
- n.{BLOCKED}gks.ru
- n.{BLOCKED}xqs.ru
- n.{BLOCKED}uf.ru
- n.{BLOCKED}fdx.ru
- n.{BLOCKED}jwgy.ru
- n.{BLOCKED}bf.ru
- n.{BLOCKED}cvx.ru
- n.{BLOCKED}etb.ru
- n.{BLOCKED}ll.ru
- n.{BLOCKED}rg.ru
- n.{BLOCKED}yg.ru
- n.{BLOCKED}icx.ru
- n.{BLOCKED}mx.ru
- n.{BLOCKED}xz.ru
- n.{BLOCKED}qbp.ru
- n.{BLOCKED}yh.ru
- n.{BLOCKED}e.ru
- n.{BLOCKED}inx.ru
- n.{BLOCKED}pxz.ru
- n.{BLOCKED}pbo.ru
- n.{BLOCKED}dam.ru
- n.{BLOCKED}vrd.ru
- n.{BLOCKED}qs.ru
- n.{BLOCKED}and.ru
- n.{BLOCKED}lqc.ru
- n.{BLOCKED}xil.ru
- n.{BLOCKED}xhw.ru
- n.{BLOCKED}jty.ru
- n.{BLOCKED}ydma.com
- n.{BLOCKED}vhe.com
- n.{BLOCKED}sqv.com
- n.{BLOCKED}xax.com
- n.{BLOCKED}hotd.com
- n.{BLOCKED}bpm.com
- n.{BLOCKED}bsj.com
- n.{BLOCKED}fsz.com
- n.{BLOCKED}uag.com
- n.{BLOCKED}lyt.com
- n.{BLOCKED}uez.com
- n.{BLOCKED}uvr.com
- n.{BLOCKED}iqf.com
- n.{BLOCKED}bib.com
- n.{BLOCKED}fpj.com
- n.{BLOCKED}bab.com
- n.{BLOCKED}tli.com
- n.{BLOCKED}asl.com
- n.{BLOCKED}hxq.com
- n.{BLOCKED}fpi.com
- n.{BLOCKED}khq.com
- n.{BLOCKED}tse.com
- n.{BLOCKED}weh.com
- n.{BLOCKED}jxo.com
- n.{BLOCKED}sjsu.com
- n.{BLOCKED}hio.com
- n.{BLOCKED}jmk.com
- n.{BLOCKED}nf.com
- n.{BLOCKED}thi.com
- n.{BLOCKED}pts.com
- n.{BLOCKED}yov.com
- n.{BLOCKED}bbb.com
- n.{BLOCKED}qaa.com
- n.{BLOCKED}cra.com
- n.{BLOCKED}kfu.com
- n.{BLOCKED}egs.com
- n.{BLOCKED}ysj.com
- n.{BLOCKED}cna.com
- n.{BLOCKED}awyu.com
- n.{BLOCKED}rqm.com
- n.{BLOCKED}jtb.com
- n.{BLOCKED}aaj.com
- n.{BLOCKED}dct.com
- n.{BLOCKED}zyr.com
- n.{BLOCKED}cxh.com
- n.{BLOCKED}qpg.com
- n.{BLOCKED}ztu.com
- n.{BLOCKED}rdo.com
- n.{BLOCKED}rhy.com
- n.{BLOCKED}kwax.com
- n.{BLOCKED}niwo.com
- n.{BLOCKED}jzt.com
- n.{BLOCKED}sxt.com
- n.{BLOCKED}mnh.com
- n.{BLOCKED}ixo.com
- n.{BLOCKED}jkk.com
- n.{BLOCKED}onc.com
- n.{BLOCKED}edd.com
- n.{BLOCKED}dzt.com
- n.{BLOCKED}klo.com
- n.{BLOCKED}typ.com
- n.{BLOCKED}wrl.com
- n.{BLOCKED}up.com
- n.{BLOCKED}hcr.com
- n.{BLOCKED}tms.com
- n.{BLOCKED}lyd.com
- n.{BLOCKED}vcy.com
- n.{BLOCKED}lmz.com
- n.{BLOCKED}ips.com
- n.{BLOCKED}gjm.com
- n.{BLOCKED}wum.com
- n.{BLOCKED}lqf.com
- n.{BLOCKED}nwc.com
- n.{BLOCKED}dec.com
- n.{BLOCKED}jw.com
- n.{BLOCKED}nzj.com
- n.{BLOCKED}idks.com
- n.{BLOCKED}bce.com
- n.{BLOCKED}ahr.com
- n.{BLOCKED}ss.com
- n.{BLOCKED}nup.com
- n.{BLOCKED}nx.com
- n.{BLOCKED}gko.com
- n.{BLOCKED}hsl.com
- n.{BLOCKED}umt.com
- n.{BLOCKED}imf.com
- n.{BLOCKED}xbr.com
- n.{BLOCKED}gu.com
- n.{BLOCKED}wylf.com
- n.{BLOCKED}mwer.com
- n.{BLOCKED}gdj.com
- n.{BLOCKED}she.com
- n.{BLOCKED}qc.com
- n.{BLOCKED}ki.com
- n.{BLOCKED}muh.com
- n.{BLOCKED}xv.com
- n.{BLOCKED}eou.com
- n.{BLOCKED}cah.com
- n.{BLOCKED}oh.com
- n.{BLOCKED}ebj.com
It does the following:
- It drops shortcut files pointing to the copy of itself in removable drives. These dropped .LNK files use the names of the folders and files (except .exe files) located on the said drives for their file names. It then sets the attributes of the original folders to Hidden to trick the user into clicking the .LNK files.
It deletes the initially executed copy of itself
SOLUTION
Step 1
Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.
Step 2
Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.
Step 3
Scan your computer with your Trend Micro product and note files detected as WORM_DORKBOT.XXSR
Step 4
Restart in Safe Mode
Step 5
Delete this registry value
Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- Windows Update Installer = "%Application Data%\WindowsUpdate\Updater.exe"
- Windows Update Installer = "%Application Data%\WindowsUpdate\Updater.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- {random filename} = "%Application Data%\Microsoft\Windows\Themes\{random filename}.exe"
- {random filename} = "%Application Data%\Microsoft\Windows\Themes\{random filename}.exe"
Step 6
- Open a command prompt.
- For Windows 2000, Windows XP, and Windows Server 2003 users, click Start>Run. In the Search box, type CMD then press Enter.
- For Windows Vista, Windows 7, and Windows Server 2008 users, click Start, type CMD in the Search input field then press Enter.
- For Windows 8, Windows 8.1, and Windows Server 2012 users, right-click on the lower-left corner of the screen, click Command Prompt.
- In the CMD console, type the following:
ATTRIB [+R | -R] [+A | -A ] [+S | -S] [+H | -H] [+I | -I] [drive:][path][file name] [/S [/D] [/L]]
Where:
+ Sets an attribute.
- Clears an attribute
R Read-only file attribute
A Archive file attribute
S System file attribute
H Hidden file attribute
I Not content indexed file attribute
[drive:][path][filename]
Specifies a file or files for attrib to process
/S Processes matching files in the current folder and all subfolders.
/D Processes folders
/L Work on the attributes of the Symbolic Link versus the target of the Symbolic Link
Example:
To unhide all files and folders (including subfolders) in drive D:
ATTRIB –H D:\* /S /D
- Repeat Step 3 for folders and files in other drives or folders.
Step 7
Search and delete this file
- {removable drive letter}:\{folder or file name of existing files}.lnk
- %User Temp%\c731200
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_DORKBOT.XXSR. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.
Step 9
Scan your computer with your Trend Micro product to delete files detected as WORM_DORKBOT.XXSR. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.
Step 10
Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.
- ipconfig.exe
- verclsid.exe
- regedit.exe
- rundll32.exe
- cmd.exe
- regsvr32.exe
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