BKDR_ZEGOST.YNQX
Backdoor:Win32/Zegost.AD (Microsoft); RDN/Generic BackDoor!bcf (McAfee); Backdoor.Trojan (Symantec); Backdoor.Win32.Farfli.kni (Kaspersky); Troj/Zegost-CY (Sophos); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse BackDoor.Generic_r.HHU (AVG)
Windows
Threat Type: Backdoor
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
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
217,155 bytes
EXE
No
11 Jul 2015
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.
Other System Modifications
This backdoor adds the following registry keys:
HKEY_LOCAL_MACHINE\SYSTEM\Group\
Group
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\Group\
Group
Group = "Default"
Dropping Routine
This backdoor drops the following files:
- %Start Menu%\Xnz.url
- %Start Menu%\Xnv.url
(Note: %Start Menu% is the Start Menu folder, where it usually is C:\Documents and Settings\{user name}\Start Menu on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu 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.)
Other Details
This backdoor connects to the following possibly malicious URL:
- {BLOCKED}0.1
This report is generated via an automated analysis system.
SOLUTION
9.750
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
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\SYSTEM
- Group
Step 3
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\SYSTEM\Group\Group
- Group = "Default"
Step 4
Search and delete these components
- %Start Menu%\Xnz.url
- %Start Menu%\Xnv.url
Step 5
Scan your computer with your Trend Micro product to delete files detected as BKDR_ZEGOST.YNQX. 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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