TROJ_RANSOM.EHA
Trojan.Win32.Buzus.lawo(Kaspersky),Win32/Filecoder.NAH trojan(NOD32),Trojan horse Ransomer.TD(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: Trojan
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This Trojan 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
518,375 bytes
EXE
Yes
03 Jul 2013
Arrival Details
This Trojan 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 Trojan drops the following files:
- %System Root%\ProgramData\local\aescrypter.exe
- %System Root%\ProgramData\local\svchost.exe
- %System Root%\ProgramData\local\undxkpwvlk.dll
- %System Root%\ProgramData\local\vpkswnhisp.dll
- %System%\csrsstub.exe
- %System%\dcomcnfgui.exe
- %System%\tcpsvcss.exe
- %System%\tracerpts.exe
- %System%\ucsvcsh.exe
- %System%\wcmtstcsys.sss
- %System Root%\how to decrypt aes files.lnk
- All Users’ %Desktop%\how to decrypt aes files.lnk
- %System Root%\decrypt\decrypt.exe
(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %Desktop% is the desktop folder, where it usually is C:\Documents and Settings\{user name}\Desktop in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\Desktop in 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.)
It creates the following folders:
- %System Root%\decrypt
- %System Root%\ProgramData\local
- %Application Data%\WinRAR
(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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 System Modifications
This Trojan deletes the following files:
- Files with any of the following extension:
- .fh
- .bkf
- .qbb
- .tib
- .001
- .113
- .abf
- .abk
- .as4
- .ate
- .ati
- .bac
- .bak
- .bck
- .bcm
- .bk1
- .bkc
- .bkp
- .bks
- .bpa
- .bpb
- .bps
- .bup
- .dna
- .fbf
- .fbw
- .ful
- .gho
- .ipd
- .jbk
- .kb2
- .mig
- .nba
- .nbf
- .nbu
- .nb7
- .nbk
- .nbs
- .npf
- .nps
- .nrs
- .oeb
- .old
- .qbk
- .qic
- .rbc
- .rbf
- .rdb
- .rrr
- .sbb
- .sn1
- .sn2
- .spf
- .spi
- .stg
- .tbk
- .uci
- .v2i
- .wbb
It adds the following registry keys:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\netprofms\Enum
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\netprofms\Security
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WdiServiceSysHost\Enum
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WdiServiceSysHost\Security
HKEY_CURRENT_USER\Software\WinRAR SFX
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\netprofms
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WdiServiceSysHost
It adds the following registry entries:
HKEY_CURRENT_USER\Software\WinRAR SFX
{%System Root%}%%WINDOWS%system32% = "%System%"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
svchost = "%System Root%\ProgramData\local\svchost.exe"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\netprofms
Type = "10"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\netprofms
Start = "2"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\netprofms
ErrorControl = "1"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\netprofms
ImagePath = "%System%\ucsvcsh.exe"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\netprofms
DisplayName = "Network List System Service"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\netprofms
ObjectName = "LocalSystem"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\netprofms
Description = "Identifies the networks to which the computer has connected, collects, stores properties for these networks, and notifies applications when these properties change."
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\netprofms\Security
Security = "{hex values 1}"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\netprofms\Enum
0 = "Root\LEGACY_NETPROFMS\0000"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\netprofms\Enum
Count = "1"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\netprofms\Enum
NextInstance = "1"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WdiServiceSysHost
Start = "2"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WdiServiceSysHost
ErrorControl = "1"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WdiServiceSysHost
Type = "10"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WdiServiceSysHost
ImagePath = "%System%\dcomcnfgui.exe"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WdiServiceSysHost
DisplayName = "Diagnostic Service System Host"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WdiServiceSysHost
ObjectName = "LocalSystem"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WdiServiceSysHost
Description = "The Diagnostic Service System Host is used by the Diagnostic Policy Service to host diagnostics that need to run in a Local Service context. If this service is stopped, any diagnostics that depend on it will no longer function."
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WdiServiceSysHost\Security
Security = "{hex values 2}"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WdiServiceSysHost\Enum
0 = "Root\LEGACY_WDISERVICESYSHOST\0000"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WdiServiceSysHost\Enum
Count = "1"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WdiServiceSysHost\Enum
NextInstance = "1"
It modifies the following registry entries:
HKEY_USERS\.DEFAULT\Software\
Microsoft\Windows\CurrentVersion\
Explorer\Shell Folders
AppData = "%System Root%\Documents and Settings\LocalService\Application Data"
(Note: The default value data of the said registry entry is %System Root%\Documents and Settings\NetworkService\Application Data.)
It deletes the following registry keys:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Control\SafeBoot
Other Details
This Trojan encrypts files with the following extensions:
- .jpeg
- .docx
- .xlsx
- .db
- .olk
- .dat
- .zip
- .rar
- .qbw
- .jpg
- .doc
- .psd
- .bmp
- .png
- .xls
- .txt
- .rtf
- .tif
- .xml
- .php
- .sxg
- .ods
- .sql
- .jpe
- .$er
- .4dd
- .aft
- .ahd
- .ask
- .azz
- .bib
- .bok
- .btr
- .cdb
- .cdb
- .crd
- .daf
- .db2
- .db3
- .dbc
- .dbs
- .dbf
- .dbv
- .df1
- .dp1
- .dsk
- .dta
- .dxl
- .eco
- .edb
- .eql
- .fcd
- .fdb
- .fic
- .fid
- .fol
- .gdb
- .hdb
- .his
- .ihx
- .jtx
- .lgc
- .mdb
- .mdf
- .mud
- .myd
- .ns2
- .ns3
- .ns4
- .nsf
- .nyf
- .odb
- .ora
- .owg
- .pan
- .pdb
- .pdb
- .pdm
- .phm
- .pwa
- .qvd
- .rsd
- .sbf
- .sdb
- .sdf
- .tcx
- .tdt
- .udb
- .v12
- .wdb
- .xld
- .zdb
- .fp7
It renames encrypted files using the following names:
- {original file name}.aes
SOLUTION
9.300
10.130.09
03 Jul 2013
10.131.00
04 Jul 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
Identify and delete files detected as TROJ_RANSOM.EHA using the Recovery Console
Step 3
Scan your computer with your Trend Micro product and note files detected as TROJ_RANSOM.EHA
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\Run
- svchost = "%System Root%\ProgramData\local\svchost.exe"
- svchost = "%System Root%\ProgramData\local\svchost.exe"
Step 5
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_CURRENT_USER\Software
- WinRAR SFX
- WinRAR SFX
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
- netprofms
- netprofms
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
- WdiServiceSysHost
- WdiServiceSysHost
Step 6
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.
- In HKEY_USERS\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders
- From: AppData = "%System Root%\Documents and Settings\LocalService\Application Data"
To: AppData = %System Root%\Documents and Settings\NetworkService\Application Data
- From: AppData = "%System Root%\Documents and Settings\LocalService\Application Data"
Step 7
Search and delete these files
- %System%\csrsstub.exe
- %System%\tcpsvcss.exe
- %System%\tracerpts.exe
- %System Root%\how to decrypt aes files.lnk
- All Users' %Desktop%\how to decrypt aes files.lnk
Step 8
Search and delete this folder
- %System Root%\decrypt
- %System Root%\ProgramData\local
- %Application Data%\WinRAR
Step 9
Scan your computer with your Trend Micro product to delete files detected as TROJ_RANSOM.EHA. 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 10
Restore this deleted registry key/value from backup
*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control
- SafeBoot
- SafeBoot
Step 11
Restore files 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 your computer again.
NOTES:
Delete the following files during the Recovery Console to disable the startup of the malware:
- %System%\ucsvcsh.exe
- %System%\dcomcnfgui.exe
- %System Root%\ProgramData\local\svchost.exe
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