BKDR_KATSLO.AB
Backdoor:Win32/Caphaw.D (Microsoft), BackDoor-FHI (McAfee), Trojan.Gen (Symantec), Trojan.Win32.Generic!SB.0 (Sunbelt), Mal/EncPk-AER (Sophos)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Backdoor
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
Downloaded from the Internet, Dropped by other malware
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.
It is injected into all running processes to remain memory resident.
It connects to a website to send and receive information.
It modifies the Internet Explorer Zone Settings.
It deletes the initially executed copy of itself.
TECHNICAL DETAILS
TCP Port 443
212,992 bytes
EXE
Yes
18 Aug 2012
Connects to URLs/IPs, Compromises system security, Collects system information
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 copies of itself into the affected system:
- User Profile%\Application Data\{random application path}\{random application name}.exe
It is injected into all running processes to remain memory resident.
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 GUID} = "%User Profile%\Application Data\{random application path}\{random application name}.exe"
Other System Modifications
This backdoor adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
NoProtectedModeBanner = "1"
Backdoor Routine
This backdoor connects to the following websites to send and receive information:
- http://{BLOCKED}tection.su/first.php?r={value}
- http://{BLOCKED}istic.cc/first.php?r={value}
- http://{BLOCKED}ard.su/first.php?r={value}
It posts the following information to its command and control (C&C) server:
- Installed Applications
- Directory and File List
- Drive Informations
- Network Information
- Username
- Computername
- OS Version
- Hardware Information
- Running Processes
Web Browser Home Page and Search Page Modification
This backdoor modifies the Internet Explorer Zone Settings.
Other Details
This backdoor deletes the initially executed copy of itself
SOLUTION
9.200
9.330.06
18 Aug 2012
9.331.00
19 Aug 2012
Step 1
For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.
Step 2
Scan your computer with your Trend Micro product and note files detected as BKDR_KATSLO.AB
Step 3
Restart in Safe Mode
Step 4
Search and delete the file detected as BKDR_KATSLO.AB
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 GUID} = "%User Profile%\Application Data\{random application path}\{random application name}.exe"
- {random GUID} = "%User Profile%\Application Data\{random application path}\{random application name}.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
- NoProtectedModeBanner = "1"
- NoProtectedModeBanner = "1"
Step 6
Reset Internet security settings
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_KATSLO.AB. 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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