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 copies of itself into the affected system and executes them:
- %Application Data%\{Random Filename}.exe
(Note: %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.)
It drops the following files:
- %Application Data%\log.html - Contains the list of encrpted files.
- %Desktop%\HELP_TO_SAVE_FILES.bmp
- %Desktop%\HELP_TO_SAVE_FILES.txt
- %Desktop%\Save_Files.lnk - Shortcut file pointing to the dropped copy
- %Application Data%\key.dat
(Note: %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.. %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.)
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
wertret = "%Application Data%\{Random Filename}.exe"
HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
wertret = "%Application Data%\{Random Filename}.exe"
Other System Modifications
This Trojan modifies the following registry entries:
HKEY_CURRENT_USER\Control Panel\Desktop
WallpaperStyle = "0"
(Note: The default value data of the said registry entry is {User Preferences}.)
HKEY_CURRENT_USER\Control Panel\Desktop
TileWallpaper = "0"
(Note: The default value data of the said registry entry is {User Preferences}.)
HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = "%Desktop%\HELP_TO_SAVE_FILES.bmp"
(Note: The default value data of the said registry entry is {User Preferences}.)
Process Termination
This Trojan terminates processes or services that contain any of the following strings if found running in the affected system's memory:
- taskmgr
- procexp
- regedit
- msconfig
- cmd.exe
Web Browser Home Page and Search Page Modification
This Trojan modifies the Internet Explorer Zone Settings.
Other Details
This Trojan connects to the following URL(s) to get the affected system's IP address:
It connects to the following website to send and receive information:
- http://{BLOCKED}ftmf7lelsa.{BLOCKED}7awmx28.com
- http://{BLOCKED}ftmf7lelsa.{BLOCKED}4iene29.com
- http://{BLOCKED}ftmf7lelsa.{BLOCKOED}b.blutmagie.de:443
- http://{BLOCKED}ftmf7lelsa.{BLOCKED}b.fi:443
It encrypts files with the following extensions:
- .3fr
- .DayZProfile
- .accdb
- .ai
- .apk
- .arch00
- .arw
- .asset
- .avi
- .bar
- .bay
- .bc6
- .bc7
- .big
- .bik
- .bkf
- .bkp
- .blob
- .bsa
- .cas
- .cdr
- .cer
- .cfr
- .cr2
- .crt
- .crw
- .css
- .csv
- .d3dbsp
- .das
- .dazip
- .db0
- .dbfv
- .dcr
- .der
- .desc
- .dmp
- .dng
- .doc
- .docm
- .docx
- .dwg
- .dxg
- .ecc
- .epk
- .eps
- .erf
- .esm
- .ff
- .flv
- .forge
- .fos
- .fpk
- .fsh
- .gdb
- .gho
- .hkdb
- .hkx
- .hplg
- .hvpl
- .ibank
- .icxs
- .indd
- .itdb
- .itl
- .itm
- .iwd
- .iwi
- .jpe
- .jpeg
- .jpg
- .js
- .kdb
- .kdc
- .kf
- .layout
- .lbf
- .litemod
- .lrf
- .ltx
- .lvl
- .m2
- .m3u
- .m4a
- .map
- .mcgame
- .mcmeta
- .mdb
- .mdbackup
- .mddata
- .mdf
- .mef
- .menu
- .mlx
- .mpqge
- .mrwref
- .ncf
- .nrw
- .ntl
- .odb
- .odc
- .odm
- .odp
- .ods
- .odt
- .orf
- .p12
- .p7b
- .p7c
- .pak
- .pdd
- .pdf
- .pef
- .pem
- .pfx
- .pkpass
- .png
- .ppt
- .pptm
- .pptx
- .psd
- .psk
- .pst
- .ptx
- .py
- .qdf
- .qic
- .r3d
- .raf
- .rar
- .raw
- .rb
- .re4
- .rgss3a
- .rim
- .rofl
- .rtf
- .rw2
- .rwl
- .sav
- .sb
- .sc2save
- .sid
- .sidd
- .sidn
- .sie
- .sis
- .slm
- .snx
- .sr2
- .srf
- .srw
- .sum
- .svg
- .syncdb
- .t12
- .t13
- .tax
- .tor
- .txt
- .unity3d
- .upk
- .vcf
- .vdf
- .vfs0
- .vpk
- .vpp_pc
- .vtf
- .w3x
- .wb2
- .wma
- .wmo
- .wmv
- .wotreplay
- .wpd
- .wps
- .x3f
- .xf
- .xlk
- .xls
- .xlsb
- .xlsm
- .xlsx
- .xxx
- .ztmp
It deletes the initially executed copy of itself
NOTES:
It creates and displays the following window to inform the user about what happened to their files and how they can restore them.
The registry modifications are for changing the affected system's wallpaper. The new wallpaper informs the user that his files are encrypted and displays the instructions on how to decrypt the files.
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
Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.
Step 3
Identify and terminate files detected as TROJ_CRYPTESLA.A
[ Learn More ]
[ back ]
- Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
- If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
To terminate the malware/grayware/spyware process:
- Scan your computer with your Trend Micro product and take note of the name of the malware/grayware/spyware detected.
- Open Windows Task Manager. To do this, press CTRL+SHIFT+ESC.
- View the list of all running programs. To do this:
• For Windows 2000, XP, Server 2003, Vista, 7 and Server 2008 users, click the Processes tab.
• For Windows 8, 8.1 and Server 2012 users, click the Details tab. - In the list of running programs, locate a malware/grayware/spyware file detected earlier.
- Select the detected files, then press either the End Task or the End Process button, depending on the version of Windows you are using.
- Do the same for the remaining detected malware/grayware/spyware files in the list of running programs.
- To check if the malware/grayware/spyware process has been terminated, close Task Manager, and then open it again.
- Close Task Manager.
Step 4
Delete this registry value
[ Learn More ]
[ back ]
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
- wertret = "%Application Data%\{Random Filename}.exe"
- In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- wertret = "%Application Data%\{Random Filename}.exe"
To delete the registry value this malware created:
- Open Registry Editor. To do this:
» For Windows 2000, Windows XP, and Windows Server 2003 users, click Start>Run, type regedit in the text box provided, and then press Enter.
» For Windows Vista, Windows 7, and Windows Server 2008 users, click the Start button, type regedit in the Search input field then press Enter.
» For Windows 8, Windows 8.1, and Windows Server 2012 users, right-click on the lower left corner of the screen, click Run, type regedit in the text box provided, and then press Enter. - In the left panel of the Registry Editor window, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Windows>CurrentVersion>Run - In the right panel, locate and delete the entry:
wertret = "%Application Data%\{Random Filename}.exe" - In the left panel of the Registry Editor window, double-click the following:
HKEY_CURRENT_USER>SOFTWARE>Microsoft>Windows>CurrentVersion>Run - In the right panel, locate and delete the entry:
wertret = "%Application Data%\{Random Filename}.exe" - Close Registry Editor.
Step 5
Search and delete this file
[ Learn More ]
[ back ]
There may be some files that are hidden. Please make sure you check the
Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
%Application Data%\key.dat
%Application Data%\log.html
%Desktop%\HELP_TO_SAVE_FILES.bmp
%Desktop%\HELP_TO_SAVE_FILES.txt
%Desktop%\Save_Files.lnk
To manually delete a malware/grayware file from an affected system:
• For Windows 2000, Windows XP, and Windows Server 2003:
- Right-click Start then click Search....
- In the File name* input box, type the following:
%Application Data%\key.dat
%Application Data%\log.html
%Desktop%\HELP_TO_SAVE_FILES.bmp
%Desktop%\HELP_TO_SAVE_FILES.txt
%Desktop%\Save_Files.lnk
- In the Look In drop-down list, select My Computer then press Enter.
- Once located, select the file then press SHIFT+DELETE to delete it.
*Note: The file name input box title varies depending on the Windows version (e.g. Search for files or folders named or All or part of the file name.).
• For Windows Vista, Windows 7, Windows Server 2008, Windows 8, Windows 8.1, and Windows Server 2012:
- Open a Windows Explorer window.
- For Windows Vista, 7, and Server 2008 users, click Start>Computer.
- For Windows 8, 8.1, and Server 2012 users, right-click on the lower left corner of the screen, then click File Explorer.
- In the Search Computer/This PC input box, type:
%Application Data%\key.dat
%Application Data%\log.html
%Desktop%\HELP_TO_SAVE_FILES.bmp
%Desktop%\HELP_TO_SAVE_FILES.txt
%Desktop%\Save_Files.lnk
- Once located, select the file then press SHIFT+DELETE to delete it.
*Note: Read the following Microsoft page if these steps do not work on Windows 7.
Step 6
Restore this modified registry value
[ Learn More ]
[ back ]
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\Control Panel\Desktop
- From: WallpaperStyle = "0"
To: WallpaperStyle = {User Preferences}
- In HKEY_CURRENT_USER\Control Panel\Desktop
- From: TileWallpaper = "0"
To: TileWallpaper = {User Preferences}
- In HKEY_CURRENT_USER\Control Panel\Desktop
- From: Wallpaper = "%Desktop%\HELP_TO_SAVE_FILES.bmp"
To: Wallpaper = {User Preferences}
To restore the registry value this malware/grayware modified:
- Open Registry Editor.
» For Windows 2000, Windows XP, and Windows Server 2003 users, click Start>Run, type regedit in the text box provided, and then press Enter.
» For Windows Vista, Windows 7, and Windows Server 2008 users, click the Start button, type regedit in the Search input field then press Enter.
» For Windows 8, Windows 8.1, and Windows Server 2012 users, right-click on the lower left corner of the screen, click Run, type regedit in the text box provided, and then press Enter. - In the left panel, double-click the following:
HKEY_CURRENT_USER>Control Panel>Desktop - In the right panel, locate the registry value:
WallpaperStyle = "0" - Right-click on the value name and choose Modify. Change the value data of this entry to:
WallpaperStyle = {User Preferences} - Again In the right panel, locate the registry value:
TileWallpaper = "0" - Right-click on the value name and choose Modify. Change the value data of this entry to:
TileWallpaper = {User Preferences} - Again In the right panel, locate the registry value:
Wallpaper = "%Desktop%\HELP_TO_SAVE_FILES.bmp" - Right-click on the value name and choose Modify. Change the value data of this entry to:
Wallpaper = {User Preferences} - Close Registry Editor.
Step 7
Scan your computer with your Trend Micro product to clean files detected as TROJ_CRYPTESLA.A. 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.
Did this description help? Tell us how we did.