DynoWiper

S9038

Malware.View on attack.mitre.org

About this malware

DynoWiper is a destructive malware associated with the 2025 Poland Wiper Attacks in December of 2025. DynoWiper is a native Windows binary that is distributed by a PowerShell script and overwrites files using data generated by the Mersenne Twister algorithm before they are deleted from the system. Multiple variants of DynoWiper have been identified, with the primary differences being that one variant shuts down the system after completing its destructive operations, and another introduces a time delay between file overwriting and deletion.

Techniques used9

Procedure examples9

TechniqueProcedure example
T1036
Masquerading

DynoWiper has been named after well-known files schtask.exe, schtask2.exe, and <redacted>_update.exe.

T1083
File and Directory Discovery

DynoWiper has used the Microsoft Windows native `FindFirstFile()` and `FindNextFile()` to recursively enumerate directories and files on the system.

T1106
Native API

DynoWiper has used multiple native Windows functions, such as `GetLogicalDrives` and `FindNextFile` for discovery and file deletion.

T1120
Peripheral Device Discovery

DynoWiper has enumerated and overwritten files on all removeable and fixed drives.

T1485
Data Destruction

DynoWiper has overwritten files with 16-byte sequences of random data generated by the Mersenne Twister algorithm using the Microsoft Windows native `CreateFileW()` function to open the file and the `SetFilePointerEx()` and `WriteFile()` functions to overwrite the file. Additionally, versions of DynoWiper can also delete files using the `DeleteFileW` API.

T1529
System Shutdown/Reboot

DynoWiper has used the Microsoft Windows native `ExitWindowsEx()` function to log off the interactive user and shutdown the system.

T1678
Delay Execution

DynoWiper has utilized a five-second delay using `Sleep(5000)` between two of the three phases of the attack that involves file overwriting, file deletion, and system reboot.

T1679
Selective Exclusion

DynoWiper has recursively enumerated directories with the exception of the following: System32, Windows, Program Files, Program Files(x86), Temp, Recycle.Bin, $Recycle.Bin, Boot, PerfLogs, AppData, Documents and Settings.

T1680
Local Storage Discovery

DynoWiper has used the Microsoft Windows native `GetLogicalDrives()` and `GetDriveType()` functions to enumerate all the drives visible to the system.

Groups that use it0

None recorded.

Campaigns1

References2

  1. CERT Polska Open source
    CERT Polska. (2026, January 30). Energy Sector Incident Report – 29 December. Retrieved April 22, 2026.
  2. ESET DynoWiper Update JAN 2026 Open source
    ESET. (2026, January 30). DynoWiper update: Technical analysis and attribution. Retrieved April 22, 2026.

Data from MITRE ATT&CK® (Enterprise). ATT&CK® is a registered trademark of The MITRE Corporation.