BKDR_QULKONWI.GHR
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Backdoor
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
This backdoor was hosted in the compromised Gizmodo Brazil website. It starts out as a fake Adobe Flash Player download.
To get a one-glance comprehensive view of the behavior of this Backdoor, refer to the Threat Diagram shown below.
![](https://documents.trendmicro.com/images/bkdr_qulkonwi_ghr.jpg)
This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
TECHNICAL DETAILS
Arrival Details
This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
Installation
This backdoor drops the following files:
- %User Temp%\{4 random numbers}.tmp
- %User Temp%\t.reg
- %Application Data%\temp.txt - This file receives the strings to be appended to addon.exe and to be deleted right after
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)
It drops the following component file(s):
- %Application Data%\WinNTService.vbs - detected as VBS_PROXY.BEE
- %All Users Profile%\javau.n - detected as VBS_PROXY.BEE
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.. %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.)
It drops the following copies of itself into the affected system:
- %All Users Profile%\addon.exe
(Note: %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.)
Other System Modifications
This backdoor adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
EnableLUA = "0"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
ConsentPromptBehaviorAdmin = "0"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
AutoConfigURL = "%All Users Profile%\javau.n"
Backdoor Routine
This backdoor connects to the following URL(s) to send and receive commands from a remote malicious user:
- http://{BLOCKED}.{BLOCKED}.203.163/rename/00006/c.php?tip=[0][WINXP][][[P]&inf=
- http://{BLOCKED}.{BLOCKED}.203.163/rename/00003/notify.php
- http://{BLOCKED}.{BLOCKED}4.com/nmupd.txt
Download Routine
This backdoor connects to the following URL(s) to download its component file(s):
- http://{BLOCKED}.{BLOCKED}.203.164/ver.vbs - It saves the downloaded file as %Application Data%\WinNtService.vbs
- http://{BLOCKED}.{BLOCKED}4.com/yes.vbs - copy of %Application Data%\WinNtService.vbs
- http://{BLOCKED}.{BLOCKED}4.com/windesktop.gif
- http://{BLOCKED}.{BLOCKED}4.com/pluginchrome.zip - It saves the downloaded file as %Application Data%\Google\Chrome\User Data\Default\pluginchrome.zip - detected as BREX_EUPUDS.GHR
NOTES:
It executes %System%\ping.exe -n 1 g.{BLOCKED}p14.com to check for connection
It may use the following backdoor commands:
- BBABORT
- BBALL
- BBCANCEL
- BBCLOSE
- BBHELP
- BBIGNORE
- BBNO
- BBOK
- BBRETRY
- BBYES
- CDROM
- CLOSEDFOLDER
- CURRENTFOLDER
- EXECUTABLE
- FLOPPY
- HARD
- KNOWNFILE
- NETWORK
- OPENFOLDER
- PREVIEWGLYPH
- RAM
- UNKNOWNFILE
- DLGTEMPLATE
- DVCLAL
- PACKAGEINFO
- TFORM1
It appends the legitimate file %User Profile%\Application Data\Mozilla\Firefox\Profiles\{random}\prefs.js:
- user_pref(network.proxy.autoconfig_url)%All Users Profile%\javau.n)
- user_pref(network.proxy.type, 2)
Drops and extracts %Application Data%\Google\Chrome\User Data\Default\pluginchrome.zip into folder %Application Data%\Google\Chrome\User Data\Default\Extensions\{random characters} which contains the ff files/components:
- getPagesSource.js
- img\flash128.png
- img\flash48.png
- img\Thumbs.db
- manifest.json
- popup.html
- popup.js
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
Remove malware/grayware files dropped/downloaded by BKDR_QULKONWI.GHR. (Note: Please skip this step if the threats listed below have already been removed.)
- VBS_PROXY.BEE
- BREX_EUPUDS.GHR
Step 4
Scan your computer with your Trend Micro product and note files detected as BKDR_QULKONWI.GHR
Step 5
Restart in Safe Mode
Step 6
Search and delete this file
- %Application Data%\temp.txt
- %User Temp%\{4 random numbers}.tmp
- %User Temp%\t.reg
- %User Temp%\flager
Step 7
Scan your computer with your Trend Micro product to delete files detected as BKDR_QULKONWI.GHR. 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 8
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.
RESTOREStep 9
Reset Internet security settings
Step 10
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_QULKONWI.GHR. 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 11
The following created files/folders/registry keys/registry entries cannot be identified by the user since there are no reference values in the created key. The only way it can be identified is by comparing the present system information with a backup. Note that the said components do not have to be deleted since it won't be harmful to the system.
- %Application Data%\Google\Chrome\User Data\Default\Extensions\{random characters}
NOTES:
Delete the following strings from %User Profile%\Application Data\Mozilla\Firefox\Profiles\{random}\prefs.js:
- user_pref(network.proxy.autoconfig_url)%All Users Profile%\javau.n)
- user_pref(network.proxy.type, 2)
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