BKDR_ZEGOST.NFU
Backdoor:Win32/Zegost.AD (Microsoft); RDN/Generic BackDoor!xy (McAfee); HEUR:Trojan.Win32.Generic (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse BackDoor.Generic_r.GCH (AVG)
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:
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
274,886 bytes
EXE
No
13 May 2014
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:
- %Windows%\nannaa.exe
(Note: %Windows% is the Windows folder, which is usually C:\Windows.)
Other System Modifications
This backdoor adds the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Pqrstu Wxyabcde Ghi
Description = "Pqrstuvw Yabcdefgh Jklmnop Rstuvwxy Bcd"
Dropping Routine
This backdoor drops the following files:
- vir0.exe
- vir1.exe
- vir2.exe
- vir3.exe
- vir4.exe
- vir5.exe
- vir6.exe
- vir7.exe
- vir8.exe
- vir9.exe
Other Details
This backdoor connects to the following possibly malicious URL:
- {BLOCKED}0.1
This report is generated via an automated analysis system.
SOLUTION
9.700
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 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\ControlSet001\Services\Pqrstu Wxyabcde Ghi
- Description = "Pqrstuvw Yabcdefgh Jklmnop Rstuvwxy Bcd"
Step 3
Search and delete these components
- vir0.exe
- vir1.exe
- vir2.exe
- vir3.exe
- vir4.exe
- vir5.exe
- vir6.exe
- vir7.exe
- vir8.exe
- vir9.exe
Step 4
Scan your computer with your Trend Micro product to delete files detected as BKDR_ZEGOST.NFU. 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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