RANSOM_DAYSCARE.A
Trojan-Ransom.Win32.Xorist.lk(Kaspersky);Ransom.CryptoTorLocker(Norton)
Windows
Threat Type: Ransomware
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
Dropped by other malware, Downloaded from the Internet
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.
It encrypts files with specific file extensions. It drops files as ransom note.
TECHNICAL DETAILS
173,056 bytes
EXE
No
01 Aug 2017
Drops files, Displays graphics/image, Displays message/message boxes, Encrypts files
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 copies of itself into the affected system:
- %User Temp%\5To5e0wK2ecObSg.exe
(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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:
- %User Temp%\bpoeedcolhdamjfc.bmp ← used as wallpaper
(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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.)
Autostart Technique
This Ransomware adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Alcmeter = %User Temp%\5To5e0wK2ecObSg.exe
Other System Modifications
This Ransomware adds the following registry keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
.SEVENDAYS
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
ZBJUOIOIQYDCAUU
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
.SEVENDAYS
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
ZBJUOIOIQYDCAUU
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
ZBJUOIOIQYDCAUU\DefaultIcon
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
ZBJUOIOIQYDCAUU\shell\open\
command
It changes the desktop wallpaper by modifying the following registry entries:
HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = %User Temp%\bpoeedcolhdamjfc.bmp
(Note: The default value data of the said registry entry is {user preference}.)
It sets the system's desktop wallpaper to the following image:
Other Details
This Ransomware does the following:
- Display the following message box after encryption:
Ransomware Routine
This Ransomware encrypts files with the following extensions:
- .zip
- .rar
- .7z
- .tar
- .gzip
- .jpg
- .jpeg
- .psd
- .cdr
- .dwg
- .max
- .bmp
- .gif
- .png
- .doc
- .docx
- .xls
- .xlsx
- .ppt
- .pptx
- .txt
- .djvu
- .htm
- .html
- .mdb
- .cer
- .p12
- .pfx
- .kwm
- .pwm
- .1cd
- .md
- .mdf
- .dbf
- .odt
- .vob
- .ifo
- .lnk
- .torrent
- .mov
- .m2v
- .3gp
- .mpeg
- .mpg
- .flv
- .avi
- .mp4
- .wmv
- .divx
- .mkv
- .mp3
- .wav
- .flac
- .ape
- .wma
- .ac3
- .exe
- .txt
It avoids encrypting files with the following strings in their file name:
- ÊÀÊ ÐÀÑØÈÔÐÎ ÀÒÜ ÔÀÉËÛ.txt
- HOW TO DECRYPT FILES.txt
It appends the following extension to the file name of the encrypted files:
- .SEVENDAYS
It drops the following file(s) as ransom note:
- {Encrypted files}\HOW TO DECRYPT FILES.txt
- %Desktop%\HOW TO DECRYPT FILES.txt
(Note: %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 leaves text files that serve as ransom notes containing the following text:
SOLUTION
9.850
13.568.08
01 Aug 2017
13.569.00
02 Aug 2017
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
Restart in Safe Mode
Step 4
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.
- HKEY_LOCAL_MACHINE\SOFTWARE\Classes\.SEVENDAYS
- HKEY_LOCAL_MACHINE\SOFTWARE\Classes\ZBJUOIOIQYDCAUU
Step 5
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
- Alcmeter = %User Temp%\5To5e0wK2ecObSg.exe
- Alcmeter = %User Temp%\5To5e0wK2ecObSg.exe
Step 6
Search and delete this file
- %User Temp%\bpoeedcolhdamjfc.bmp
- %User Temp%\5To5e0wK2ecObSg.exe
- {Encrypted files}\HOW TO DECRYPT FILES.txt
- %Desktop%\HOW TO DECRYPT FILES.txt
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as RANSOM_DAYSCARE.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.
Step 8
Reset your Desktop properties
Step 9
Restore encrypted files from backup.
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