BKDR_ZAPCHAST.IY
Trojan-Spy.Win32.Zapchast.u(Kaspersky)
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
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 executes commands from a remote malicious user, effectively compromising the affected system.
It deletes itself after execution.
TECHNICAL DETAILS
80,328 bytes
EXE
Yes
04 Sep 2013
Compromises system security
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 and executes them:
- %System%\ccwap.exe
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- PpPPpPPpPPpPPpPPpP
Autostart Technique
This backdoor adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunOnce
avatar = "%System%\ccwap.exe 1 2"
Other System Modifications
This backdoor adds the following registry keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{random}
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{random}
StubPath = "%System%\ccwap.exe 1 2"
Backdoor Routine
This backdoor executes the following commands from a remote malicious user:
- Download File
- Download and Execute File
- Update Itself
- Perform remote shell command
It connects to the following URL(s) to send and receive commands from a remote malicious user:
- www.{BLOCKED}ver.{BLOCKED}o.com
- {BLOCKED}p.{BLOCKED}ver.ygto.com
Other Details
This backdoor deletes itself after execution.
NOTES:
It searches for AV-related files:
- ESET
- Avira
- Trend Micro
- AVAST
- McAfee
- Panda Security
- AVG
- Kaspersky
- Symantec
- Norton
SOLUTION
9.300
10.258.01
04 Sep 2013
10.259.00
05 Sep 2013
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
Restart in Safe Mode
Step 3
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components
- {random}
- {random}
Step 4
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce
- avatar = "%System%\ccwap.exe 1 2"
- avatar = "%System%\ccwap.exe 1 2"
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_ZAPCHAST.IY. 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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