BKDR_BLOHI.HK
Windows 2000, Windows XP, Windows Server 2003
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
3,342,334 bytes
EXE
No
16 Nov 2013
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 creates the following folders:
- %System Root%\DOCUME~1
- %System Root%\DOCUME~1\Wilbert
- %User Profile%\LOCALS~1
- %User Temp%\nst9.tmp
- %User Temp%\nst9.tmp\V3Kill
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)
Other System Modifications
This backdoor modifies the following file(s):
- %System%\MSWINSCK.ocx
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
It deletes the following files:
- %User Temp%\nse1.tmp
- %User Temp%\nsi5.tmp
- %User Temp%\nst9.tmp
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)
It adds the following registry keys:
HKEY_LOCAL_MACHINE\SOFTWARE\AhnLab\
V3IS2007
HKEY_LOCAL_MACHINE\SOFTWARE\AhnLab\
V3IS80
Dropping Routine
This backdoor drops the following files:
- %User Temp%\Control.exe
- %User Temp%\gamehackkill.exe
- %Windows%\SysWOW64\MSWINSCK.ocx
- %User Temp%\nsd7.tmp
- %User Temp%\nst9.tmp\V3Kill\0asc.scd
- %User Temp%\nst9.tmp\V3Kill\0en_us.scd
- %User Temp%\nst9.tmp\V3Kill\0ja_jp.scd
- %User Temp%\nst9.tmp\V3Kill\0ja_jp2.scd
- %User Temp%\nst9.tmp\V3Kill\0ko_kr.scd
- %User Temp%\nst9.tmp\V3Kill\0sccure.scd
- %User Temp%\nst9.tmp\V3Kill\0spe2a.scd
- %User Temp%\nst9.tmp\V3Kill\0spe3f.scd
- %User Temp%\nst9.tmp\V3Kill\0spe3h.scd
- %User Temp%\nst9.tmp\V3Kill\0spe3w.scd
- %User Temp%\nst9.tmp\V3Kill\0spe4p.scd
- %User Temp%\nst9.tmp\V3Kill\0speexp.scd
- %User Temp%\nst9.tmp\V3Kill\0spepl.scd
- %User Temp%\nst9.tmp\V3Kill\0sperl.scd
- %User Temp%\nst9.tmp\V3Kill\0sscrpt.scd
- %User Temp%\nst9.tmp\V3Kill\0swhost.scd
- %User Temp%\nst9.tmp\V3Kill\0swwcb.scd
- %User Temp%\nst9.tmp\V3Kill\0zh_cn.scd
- %User Temp%\nst9.tmp\V3Kill\0zh_tw.scd
- %User Temp%\nst9.tmp\V3Kill\AHAWKE.dll
- %User Temp%\nst9.tmp\V3Kill\AHAWKENT.sys
- %User Temp%\nst9.tmp\V3Kill\AKDVE.exe
- %User Temp%\nst9.tmp\V3Kill\AhnSZE.dll
- %User Temp%\nst9.tmp\V3Kill\BTScan.exe
- %User Temp%\nst9.tmp\V3Kill\MeDCore.dll
- %User Temp%\nst9.tmp\V3Kill\TfFRegNt.sys
- %User Temp%\nst9.tmp\V3Kill\V3Exclusive.com
- %User Temp%\nst9.tmp\V3Kill\V3Kill.ini
- %User Temp%\nst9.tmp\V3Kill\asc_asd.dll
- %User Temp%\nst9.tmp\V3Kill\asc_bse.dll
- %User Temp%\nst9.tmp\V3Kill\asc_com.dll
- %User Temp%\nst9.tmp\V3Kill\asc_dh.dll
- %User Temp%\nst9.tmp\V3Kill\asc_fse.dll
- %User Temp%\nst9.tmp\V3Kill\asc_intg.dll
- %User Temp%\nst9.tmp\V3Kill\asc_main.dll
- %User Temp%\nst9.tmp\V3Kill\asc_mmgr.dll
- %User Temp%\nst9.tmp\V3Kill\asc_reg.dll
- %User Temp%\nst9.tmp\V3Kill\asc_sec.dll
- %User Temp%\nst9.tmp\V3Kill\asc_sse.dll
- %User Temp%\nst9.tmp\V3Kill\asc_unp.dll
- %User Temp%\nst9.tmp\V3Kill\exclv7.dll
- %User Temp%\nst9.tmp\V3Kill\fse_base.dll
- %User Temp%\nst9.tmp\V3Kill\fse_dos.dll
- %User Temp%\nst9.tmp\V3Kill\fse_fact.dll
- %User Temp%\nst9.tmp\V3Kill\fse_file.dll
- %User Temp%\nst9.tmp\V3Kill\fse_mach.dll
- %User Temp%\nst9.tmp\V3Kill\fse_pe.dll
- %User Temp%\nst9.tmp\V3Kill\fse_pe2.dll
- %User Temp%\nst9.tmp\V3Kill\gfs_base.dll
- %User Temp%\nst9.tmp\V3Kill\gfs_fact.dll
- %User Temp%\nst9.tmp\V3Kill\gfs_file.dll
- %User Temp%\nst9.tmp\V3Kill\gfs_mem.dll
- %User Temp%\nst9.tmp\V3Kill\gfs_mmap.dll
- %User Temp%\nst9.tmp\V3Kill\gfs_ole.dll
- %User Temp%\nst9.tmp\V3Kill\gfs_os.dll
- %User Temp%\nst9.tmp\V3Kill\gfs_proc.dll
- %User Temp%\nst9.tmp\V3Kill\gfs_strg.dll
- %User Temp%\nst9.tmp\V3Kill\gfs_util.dll
- %User Temp%\nst9.tmp\V3Kill\gfs_zip.dll
- %User Temp%\nst9.tmp\V3Kill\moduler.scd
- %User Temp%\nst9.tmp\V3Kill\modules.scd
- %User Temp%\nst9.tmp\V3Kill\option.scd
- %User Temp%\nst9.tmp\V3Kill\private.asd
- %User Temp%\nst9.tmp\V3Kill\privext.asd
- %User Temp%\nst9.tmp\V3Kill\v3as.exe
- %User Temp%\nst9.tmp\V3Kill\v3pro32e.dll
- %User Temp%\nst9.tmp\V3Kill\v3pro32n.dll
- %User Temp%\nst9.tmp\V3Kill\v3pro32s.dll
- %User Temp%\VTMPO1584
Other Details
This backdoor connects to the following possibly malicious URL:
- http://pds26.{BLOCKED}s.com/pds/201309/09/58/mswinsck.ocx
This report is generated via an automated analysis system.
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
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\AhnLab
- V3IS2007
- In HKEY_LOCAL_MACHINE\SOFTWARE\AhnLab
- V3IS80
Step 3
Search and delete these components
- %User Temp%\Control.exe
- %User Temp%\gamehackkill.exe
- %Windows%\SysWOW64\MSWINSCK.ocx
- %User Temp%\nsd7.tmp
- %User Temp%\nst9.tmp\V3Kill\0asc.scd
- %User Temp%\nst9.tmp\V3Kill\0en_us.scd
- %User Temp%\nst9.tmp\V3Kill\0ja_jp.scd
- %User Temp%\nst9.tmp\V3Kill\0ja_jp2.scd
- %User Temp%\nst9.tmp\V3Kill\0ko_kr.scd
- %User Temp%\nst9.tmp\V3Kill\0sccure.scd
- %User Temp%\nst9.tmp\V3Kill\0spe2a.scd
- %User Temp%\nst9.tmp\V3Kill\0spe3f.scd
- %User Temp%\nst9.tmp\V3Kill\0spe3h.scd
- %User Temp%\nst9.tmp\V3Kill\0spe3w.scd
- %User Temp%\nst9.tmp\V3Kill\0spe4p.scd
- %User Temp%\nst9.tmp\V3Kill\0speexp.scd
- %User Temp%\nst9.tmp\V3Kill\0spepl.scd
- %User Temp%\nst9.tmp\V3Kill\0sperl.scd
- %User Temp%\nst9.tmp\V3Kill\0sscrpt.scd
- %User Temp%\nst9.tmp\V3Kill\0swhost.scd
- %User Temp%\nst9.tmp\V3Kill\0swwcb.scd
- %User Temp%\nst9.tmp\V3Kill\0zh_cn.scd
- %User Temp%\nst9.tmp\V3Kill\0zh_tw.scd
- %User Temp%\nst9.tmp\V3Kill\AHAWKE.dll
- %User Temp%\nst9.tmp\V3Kill\AHAWKENT.sys
- %User Temp%\nst9.tmp\V3Kill\AKDVE.exe
- %User Temp%\nst9.tmp\V3Kill\AhnSZE.dll
- %User Temp%\nst9.tmp\V3Kill\BTScan.exe
- %User Temp%\nst9.tmp\V3Kill\MeDCore.dll
- %User Temp%\nst9.tmp\V3Kill\TfFRegNt.sys
- %User Temp%\nst9.tmp\V3Kill\V3Exclusive.com
- %User Temp%\nst9.tmp\V3Kill\V3Kill.ini
- %User Temp%\nst9.tmp\V3Kill\asc_asd.dll
- %User Temp%\nst9.tmp\V3Kill\asc_bse.dll
- %User Temp%\nst9.tmp\V3Kill\asc_com.dll
- %User Temp%\nst9.tmp\V3Kill\asc_dh.dll
- %User Temp%\nst9.tmp\V3Kill\asc_fse.dll
- %User Temp%\nst9.tmp\V3Kill\asc_intg.dll
- %User Temp%\nst9.tmp\V3Kill\asc_main.dll
- %User Temp%\nst9.tmp\V3Kill\asc_mmgr.dll
- %User Temp%\nst9.tmp\V3Kill\asc_reg.dll
- %User Temp%\nst9.tmp\V3Kill\asc_sec.dll
- %User Temp%\nst9.tmp\V3Kill\asc_sse.dll
- %User Temp%\nst9.tmp\V3Kill\asc_unp.dll
- %User Temp%\nst9.tmp\V3Kill\exclv7.dll
- %User Temp%\nst9.tmp\V3Kill\fse_base.dll
- %User Temp%\nst9.tmp\V3Kill\fse_dos.dll
- %User Temp%\nst9.tmp\V3Kill\fse_fact.dll
- %User Temp%\nst9.tmp\V3Kill\fse_file.dll
- %User Temp%\nst9.tmp\V3Kill\fse_mach.dll
- %User Temp%\nst9.tmp\V3Kill\fse_pe.dll
- %User Temp%\nst9.tmp\V3Kill\fse_pe2.dll
- %User Temp%\nst9.tmp\V3Kill\gfs_base.dll
- %User Temp%\nst9.tmp\V3Kill\gfs_fact.dll
- %User Temp%\nst9.tmp\V3Kill\gfs_file.dll
- %User Temp%\nst9.tmp\V3Kill\gfs_mem.dll
- %User Temp%\nst9.tmp\V3Kill\gfs_mmap.dll
- %User Temp%\nst9.tmp\V3Kill\gfs_ole.dll
- %User Temp%\nst9.tmp\V3Kill\gfs_os.dll
- %User Temp%\nst9.tmp\V3Kill\gfs_proc.dll
- %User Temp%\nst9.tmp\V3Kill\gfs_strg.dll
- %User Temp%\nst9.tmp\V3Kill\gfs_util.dll
- %User Temp%\nst9.tmp\V3Kill\gfs_zip.dll
- %User Temp%\nst9.tmp\V3Kill\moduler.scd
- %User Temp%\nst9.tmp\V3Kill\modules.scd
- %User Temp%\nst9.tmp\V3Kill\option.scd
- %User Temp%\nst9.tmp\V3Kill\private.asd
- %User Temp%\nst9.tmp\V3Kill\privext.asd
- %User Temp%\nst9.tmp\V3Kill\v3as.exe
- %User Temp%\nst9.tmp\V3Kill\v3pro32e.dll
- %User Temp%\nst9.tmp\V3Kill\v3pro32n.dll
- %User Temp%\nst9.tmp\V3Kill\v3pro32s.dll
- %User Temp%\VTMPO1584
Step 4
Search and delete these folders
- %System Root%\DOCUME~1
- %System Root%\DOCUME~1\Wilbert
- %User Profile%\LOCALS~1
- %User Temp%\nst9.tmp
- %User Temp%\nst9.tmp\V3Kill
Step 5
Scan your computer with your Trend Micro product to delete files detected as BKDR_BLOHI.HK. 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.
Step 6
Restore deleted/modified files and/or registry entries from backup
*Note: Only Microsoft-related files/keys/values will be restored. If this malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.
- %System%\MSWINSCK.ocx
Step 7
Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.
- %User Temp%\nse1.tmp
- %User Temp%\nsi5.tmp
- %User Temp%\nst9.tmp
Did this description help? Tell us how we did.