BKDR_KULUOZ.QWJ
TrojanDownloader:Win32/Kuluoz (Microsoft), Trojan.Win32.Kuluoz.b (v) (VIPRE), W32/Dofoil.AO!tr (Fortinet)
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 arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It 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
40,960 bytes
EXE
Yes
17 Jun 2013
Arrival Details
This backdoor arrives as an attachment to email messages spammed by other malware/grayware or malicious users.
It 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:
- {initial malware copy's directory}\{initinial malware file name}.txt
It drops the following copies of itself into the affected system:
- %AppDataLocal%\{random}.exe
(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local on Windows Vista and 7.)
Autostart Technique
This backdoor adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{random} = "%Application Data%\{random}.exe"
Other System Modifications
This backdoor adds the following registry keys:
HKEY_CURRENT_USER\SOFTWARE\{random}
It adds the following registry entries as part of its installation routine:
HKEY_CURRENT_USER\SOFTWARE\{random}
{random} = "{hex values}"
Other Details
This backdoor connects to the following possibly malicious URL:
- http://{BLOCKED}.131.225:8080/{generated value}
- http://{BLOCKED}.47.151:8080/{generated value}
- http://{BLOCKED}.208.180:8090/{generated value}
- http://{BLOCKED}.139.235:8080/{generated value}
- http://{BLOCKED}.5.102:8080/{generated value}
- http://{BLOCKED}.6.40:8080/{generated value}
- http://{BLOCKED}.12.83:8080/{generated value}
- http://{BLOCKED}.132.29:8080/{generated value}
- http://{BLOCKED}.226.51:8080/{generated value}
- http://{BLOCKED}.253.250:8080/{generated value}
- http://{BLOCKED}.226.241:8080/{generated value}
It opens the following files:
- {initial malware copy's directory}\{initinial malware file name}.txt
SOLUTION
9.300
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
Scan your computer with your Trend Micro product and note files detected as BKDR_KULUOZ.QWJ
Step 3
Restart in Safe Mode
Step 4
Delete this registry key
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
- {random}
- {random}
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
- {random} = %AppDataLocal%\{random}.exe
- {random} = %AppDataLocal%\{random}.exe
Step 6
Search and delete this file
- {initial malware copy's directory}\{initinial malware file name}.txt
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_KULUOZ.QWJ. 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.
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