Residual Trace

Category: OSINT

Challenge Overview

Residual Trace required locating a historical Linux kernel panic log related to the Mr. Robot ARG and extracting a specific value from it.

Approach

Researching the ARG led to archived resources, including the kernel_panic.log preserved in community repositories. Searching the log for the NOHZ: entry revealed:

Located the tykoth/MrRobotARG GitHub repository, which archives ARG content including a kernel_panic.log file.

Found the kernel_panic.log mirrored on Pastebin (pastebin.com/2JNfLPwa), posted September 7, 2016, containing the full kernel log

NOHZ: local_softirq_pending 40

Using the required flag format produced:

XPL8{local_softirq_pending_40}

Conclusion

This challenge rewarded effective OSINT and archival research rather than technical exploitation.