~/challenges $ cat weekly/11_power_matrix_at_skyline_facility.md
Smart Buildings / Industrial Protocols Easy–Medium
Live · Week 11
CHALLENGE #11 · Released 30 June 2026

Power Matrix at SkyLine Facility

REWARD +200 pts

Briefing

intel://sss/briefing_11.txt

INTELSkyLine Data Center, Pod 4, 08:42 local. Thousands of high-density server stacks behind a single Building Management System. Breakers, coolers, automated failover — every amp accounted for, until it isn’t.

Our boundary scanners lit up on a rogue management interface exposed to an auxiliary network segment. No login prompt. No banner. It belongs to a legacy industrial Power Distribution Unit monitoring rack row 12.

The page doesn’t render a dashboard. It dumps the raw Modbus holding register map straight to the browser. Voltage, current, breaker state — and a block of unassigned registers a maintenance contractor used as scratchpad space during a recent firmware sync.

Watch the buffer. One block was rewritten on the fly. A duplicate transmission was overridden mid-stream, and the corrected payload sits one row below the broken one.

Objective

Decode the hex block hidden in the Modbus register dump and submit it as the flag.

Evidence

.html
index.html
html · exposed PDU register dump
↓ Download

Capture the Flag

Submit your solution · +200 pts on success
Format: GRID-2026-XXXX
One submission per solve. Points post to the leaderboard on verify.