Windows batch, 3 bytes, no arguments

[gremlinbeet]

---BEGIN BGGPx--- Submit Date: 2024-07-01 BGGP Challenge Number: 5 Author: gremlinbeet Contact Info (Optional): Online Presence (Website/Social Media): https://github.com/gremlinbeet Target File Type: Windows batch (.bat) File Size: 3 SHA256 Hash: F7121F50119B73D3A6835A542EA147FD1145B24CD22226ED632814205D1B8BFC Target Environment (How do we run the file?): just double click Any additional info?: filename MUST be as follows: a&powershell -c iex(('[Net.WebClient]__new().DownloadFile(''https_--binary.golf-5-5'',[Environment]__GetFolderPath(''Startup'')+''-5.txt'');shutdown -r -t 5'-replace'_',[char]58)-replace'-',[char]47)&.bat. During batch execution cmd will display some benign errors, and then system will reboot. Downloaded file contents will be displayed automatically in .txt-associated app shortly after reboot and login. Link to PoC video, screenshot, or console output, if any: Link to writeup, if any: https://github.com/gremlinbeet/binarygolf/blob/main/bggp5.batch3.adoc File contents (base64 encoded please): JX4w File contents (cleartext for quick reference): %~0 ---END BGGPx---

Minor edit 2024-07-04: fixed copypasta issue in base64 encoding, removed "no-reboot" chicken variant. It's still available in writeup. No change to actual contents or filename.

[neuschaefer]

ah, "no" "arguments" (except argv[0]) :)

[gremlinbeet]

ah, "no" "arguments" (except argv[0]) :)

Hey! No arguments explicitly specified by user 😠

Nitpick more, and the next entry will degauss & BSOD after displaying contents. 🤣

[VVX7]

Nitpick more, and the next entry will degauss & BSOD after displaying contents.

Yes, good.

[peterferrie]

---BEGIN VERIFICATION--- Reviewer: qkumba Review Date: 8-july SHA256: F7121F50119B73D3A6835A542EA147FD1145B24CD22226ED632814205D1B8BFC Score: 4913 Note: arguments affect score ---END VERIFICATION---

[peterferrie]

Thank you, your entry is added.