Arrival Details
This Ransomware 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 Ransomware drops the following files:
- %User Temp%\{random characters}-.tmp
- %User Temp%\{random characters}-.0.cs
- %User Temp%\{random characters}-.dll
- %User Temp%\{random characters}-.cmdline
- %User Temp%\{random characters}-.out
- %User Temp%\{random characters}-.err
- %User Temp%\{random characters}-.pdb
- %User Temp%\{random characters}.tmp
- %User Temp%\{random characters}.0.cs
- %User Temp%\{random characters}.dll
- %User Temp%\{random characters}.cmdline
- %User Temp%\{random characters}.out
- %User Temp%\{random characters}.err
- %User Temp%\{random characters}.pdb
(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(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
It adds the following processes:
- %Windows%\Microsoft.NET\Framework\{version}\csc.exe /noconfig /fullpaths @"%User Temp%\{random characters}-.cmdline"
- %Windows%\Microsoft.NET\Framework\{version}\cvtres.exe /NOLOGO /READONLY /MACHINE:IX86 "/OUT:%User Temp%\{random characters}.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(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
Other System Modifications
This Ransomware adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\{8 random characters}
{8 random characters} = {hex values}
HKEY_CURRENT_USER\Software\{8 random characters}
{8 random characters} = {hex values}
Process Termination
This Ransomware terminates the following services if found on the affected system:
- *backup*
- *sql*
- AcronisAgent
- AcrSch2Svc
- acrsch2svc*
- apach*
- ARSM
- backup*
- cbvscserv*
- dc*32
- firebird*
- hMailServer
- IASJet
- IBM Domino*
- ibmiasrw
- IISADMIN
- Lotus*
- MMS
- mr2kserv
- MSExchange*
- omsad
- QB*
- QuickBooksDB*
- server Administrator
- ShadowProtectSvc
- Simply Accounting Database Connection Manager
- SP*4
- SPXService
- sql*
- stc_endpt_svc
- StorageCraft ImageManager
- teamviewer
- veeam*
- vsnapvss
- wbengine
- wrsvc
It terminates the following processes if found running in the affected system's memory:
- *sql*
- agent*
- agntsvc.exe
- apach*
- b1*
- ba*
- bd2*
- be*
- bes10*
- black*
- cbservi*
- cbvscserv*
- cfdot*
- coldfus*
- db*
- dbeng50.exe
- dbsnmp.exe
- encsvc.exe
- excel.exe
- fdlaunch*
- firefoxconfig.exe
- hMailServer*
- IBM*
- infopath.exe
- jetty.exe
- msaccess.exe
- msdtssr*
- msmdsrv*
- mspub.exe
- mydesktopqos.exe
- mydesktopservice.exe
- nservice.exe
- nslsvice.exe
- ntrtscan.exe
- ocautoupds.exe
- ocomm.exe
- ocssd.exe
- onenote.exe
- oracle*
- oracle.exe
- outlook.exe
- pg*
- postg*
- powerpnt.exe
- QB*
- report*
- sage*
- sap*
- sqbcoreservice.exe
- sql*
- store.exe
- swag*
- swstrtr*
- synctime.exe
- tbirdconfig.exe
- team*
- thebat.exe
- thebat64.exe
- thunderbird.exe
- vee*
- visio.exe
- wbengine*
- winword.exe
- wordpad.exe
- wrsa.exe
- xfssvccon.exe
Other Details
This Ransomware adds the following registry keys:
HKEY_LOCAL_MACHINE\SOFTWARE\{8 random characters}
HKEY_CURRENT_USER\Software\{8 random characters}
Ransomware Routine
This Ransomware avoids encrypting files with the following strings in their file name:
- autorun.inf
- boot.ini
- bootfont.bin
- bootmgr
- bootnxt
- bootsect.bak
- desktop.ini
- gdipfont*.dat
- iconcache.db
- ntldr
- ntuser.dat
- ntuser.dat*
- ntuser.ini
- thumbs.db
- usrclass.dat
- usrclass.dat*
It avoids encrypting files with the following strings in their file path:
- *$windows.~ws
- *:\program file*\vmwaree
- *:\users\*\*tempmp
- *:\users\*\appdata\*\microsoftsoft"
- *:\windows"
- *:\winnt"
- *\program file*\common files\*shareded
- *\program file*\common files\reference ass*s*
- *\program file*\common files\systemem
- *\program file*\cuass*
- *\program file*\microsoft gamess
- *\program file*\vmwaree
- *\program file*\windows media*
- *\program file*\windows ntt
- *\program file*\windows photo*
- *\program file*\windows portable*
- *\program file*\windows side*
- *\program file*\windowspowershelll
- *\windows\cache**"
- *appdata*microsoft
- *appdata*packages
- *boot
- *dvd maker
- *Internet Explorer
- *media player
- *microsoft\provisioning
- *Mozilla
- *Mozilla*
- *msocache
- *Old Firefox data
- *perflogs
- *system volume information
- *temporary internet*
- *windows defender
- *windows.old
- \*\users\*\*temptemp"
- \*\users\*\appdata\*\microsoftrosoft
- \*\windowsws
- \*\winntnt"
It appends the following extension to the file name of the encrypted files:
It drops the following file(s) as ransom note:
- {Encrypted Directory}\{6 random characters}-Readme.txt

It avoids encrypting files with the following file extensions:
- .386
- .adv
- .ani
- .bat
- .cab
- .clb
- .cmd
- .com
- .cpl
- .cur
- .deskthemepack
- .diagcab
- .diagcfg
- .diagpkg
- .dll
- .drv
- .exe
- .hlp
- .hta
- .icl
- .icns
- .ico
- .ics
- .idx
- .key
- .ldf
- .lnk
- .lock
- .mod
- .mpa
- .msc
- .msi
- .msp
- .msstyles
- .msu
- .mui
- .nls
- .nomedia
- .ocx
- .prf
- .ps1
- .regtrans-ms
- .rom
- .rtp
- .scr
- .shs
- .spl
- .sys
- .theme
- .themepack
- .wpx
Step 1
Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 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
Delete this registry value
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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\{8 random characters}
- {8 random characters} = {hex values}
- In HKEY_CURRENT_USER\Software\{8 random characters}
- {8 random characters} = {hex values}
To delete the registry value this malware created:
- Open Registry Editor. To do this:
» For Windows 7 and Windows Server 2008 (R2) users, click the Start button, type regedit in the Search input field then press Enter.
» For Windows 8, Windows 8.1, 10, and Windows Server 2012 (R2) 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>{8 random characters} - In the right panel, locate and delete the entry:
{8 random characters} = {hex values} - In the left panel of the Registry Editor window, double-click the following:
HKEY_CURRENT_USER>Software>{8 random characters} - In the right panel, locate and delete the entry:
{8 random characters} = {hex values} - Close Registry Editor.
Step 4
Delete this registry key
[ 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\{8 random characters}
- In HKEY_CURRENT_USER\Software\{8 random characters}
To delete registry keys this malware/grayware created:
- Open Registry Editor. To do this:
» For Windows 7 and Server 2008 (R2) users, click the Start button, type regedit in the Search input field then press Enter.
» For Windows 8, 8.1, 10, and Server 2012 (R2) 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>{8 random characters} - Still in the left panel, locate and delete the key:
(null) - In the left panel of the Registry Editor window, double-click the following:
HKEY_CURRENT_USER>Software>{8 random characters} - Still in the left panel, locate and delete the key:
(null) - Close Registry Editor.
Step 5
Search and delete this file
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[ 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.
- {Encrypted Directory}\{6 random characters}-Readme.txt
- %User Temp%\{random characters}-.tmp
- %User Temp%\{random characters}-.0.cs
- %User Temp%\{random characters}-.dll
- %User Temp%\{random characters}-.cmdline
- %User Temp%\{random characters}-.out
- %User Temp%\{random characters}-.err
- %User Temp%\{random characters}-.pdb
- %User Temp%\{random characters}.tmp
- %User Temp%\{random characters}.0.cs
- %User Temp%\{random characters}.dll
- %User Temp%\{random characters}.cmdline
- %User Temp%\{random characters}.out
- %User Temp%\{random characters}.err
- %User Temp%\{random characters}.pdb
To manually delete a malware/grayware file from an affected system:
•For Windows 7, Windows Server 2008 (R2), Windows 8, Windows 8.1, Windows 10, and Windows Server 2012 (R2):
- Open a Windows Explorer window.
- For Windows 7 and Server 2008 (R2) users, click Start>Computer.
- For Windows 8, 8.1, 10, and Server 2012 (R2) users, right-click on the lower-left corner of the screen,then click File Explorer.
- In the Search Computer/This PC input box, type:
- {Encrypted Directory}\{6 random characters}-Readme.txt
- %User Temp%\{random characters}-.tmp
- %User Temp%\{random characters}-.0.cs
- %User Temp%\{random characters}-.dll
- %User Temp%\{random characters}-.cmdline
- %User Temp%\{random characters}-.out
- %User Temp%\{random characters}-.err
- %User Temp%\{random characters}-.pdb
- %User Temp%\{random characters}.tmp
- %User Temp%\{random characters}.0.cs
- %User Temp%\{random characters}.dll
- %User Temp%\{random characters}.cmdline
- %User Temp%\{random characters}.out
- %User Temp%\{random characters}.err
- %User Temp%\{random characters}.pdb
- 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 and Windows Server 2008 (R2).
Step 6
Scan your computer with your Trend Micro product to delete files detected as Ransom.PS1.NETWALKER.B. 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 the following Trend Micro Support pages for more information:
Step 7
Restore encrypted files from backup.
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