Operation Clean Stream

Scenario You have intercepted a raw telemetry log from a rogue IoT device. The payload is hidden within lines tagged as MSG_ID.

Task

1. Filter lines with MSG_ID.
2. Extract the 4th column (payload).
3. Remove adjacent duplicates.
4. Concatenate and decode the Base64 string.

[INFO] init connection
[DATA] MSG_ID 101 Q1RGe
[DATA] MSG_ID 101 Q1RGe
[WARN] high latency detected
[DATA] MSG_ID 102 3c3Ry
[DATA] MSG_ID 102 3c3Ry
[DATA] MSG_ID 102 3c3Ry
[INFO] retrying packet
[DATA] MSG_ID 103 ZWFtX
[DATA] MSG_ID 104 2xhYl
[DATA] MSG_ID 104 2xhYl
[ERR ] connection flap
[DATA] MSG_ID 105 9raW5
[DATA] MSG_ID 105 9raW5
[DATA] MSG_ID 106 nfQo=
[INFO] stream closed

grep "MSG_ID" stream.log | awk '{print $4}' | uniq | tr -d '\n' | base64 -d