For the best experience, use a player that supports MKV and 1080p streaming sources natively:

Follow the prompts to install the software on your computer. Open the File: Right-click your MKV file, select "Open With," and choose your new media player. Check Subtitles:

A monitor capable of displaying at least 1920x1080 resolution.

: The "mkv" at the end of your string indicates a Matroska container. This feature would pre-scan the file's internal streams (HEVC, AAC, etc.) and automatically download the necessary legal codecs if your system doesn't support them, ensuring the "install" results in a playable file immediately. Subtitle Synchronization Engine

However, this appears to be a — not a legitimate software or media file.

scan downloaded files with updated antivirus software.