In-browser labs
Read the artifact. Name what matters.
Four drills with no virtual machine and no network. Each sample is fictional. You identify the method, the claims, the certificate fields, or the scan pattern. Nothing here forges a token or sends a packet.
Authorized testing only. Practice on systems you own, isolated labs, or targets with written permission. Unauthorized access is illegal.
Read an HTTP request
A fictional request to lab.opsfield.example. Separate the method, the path, the headers, and the body.
POST /api/v1/notes HTTP/1.1
Host: lab.opsfield.example
Authorization: Bearer lab-demo-token
Content-Type: application/json
Accept: application/json
{"title":"scope notes","owner":"avery"}Inspect a JWT
Decode the header and payload only. The third segment is not a real signature and is not checked. This drill does not modify the token.
eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJsYWItdXNlciIsIm5hbWUiOiJBdmVyeSBDaGVuIiwicm9sZSI6InJlYWRlciIsImlzcyI6Im9wc2ZpZWxkLWxhYiIsImF1ZCI6ImFjYWRlbXkiLCJleHAiOjE4OTM0NTYwMDB9.signature-not-checked
Header
{
"alg": "HS256",
"typ": "JWT"
}Payload
{
"sub": "lab-user",
"name": "Avery Chen",
"role": "reader",
"iss": "opsfield-lab",
"aud": "academy",
"exp": 1893456000
}The signature segment is the literal text signature-not-checked. It is not verified and there is nothing to forge.
Read a certificate
A text summary of a lab certificate. No private key is included. Name the subject, the issuer, and the expiry.
Subject: CN=lab.opsfield.example Issuer: CN=OpsField Lab CA Not before: 2026-01-15 Not after: 2027-01-15 SAN: DNS:lab.opsfield.example Key usage: digitalSignature
See that a scan happened
A fictional firewall and app log. Decide which source looks like a port scan, and which line is an ordinary login. No commands.
2026-10-04T14:02:11Z fw accept src=10.8.0.15 dst=10.8.0.40 proto=tcp dport=22 2026-10-04T14:02:12Z fw accept src=10.8.0.15 dst=10.8.0.40 proto=tcp dport=80 2026-10-04T14:02:12Z fw accept src=10.8.0.15 dst=10.8.0.40 proto=tcp dport=443 2026-10-04T14:02:13Z fw accept src=10.8.0.15 dst=10.8.0.40 proto=tcp dport=445 2026-10-04T14:02:14Z fw accept src=10.8.0.15 dst=10.8.0.40 proto=tcp dport=3389 2026-10-04T14:02:18Z fw accept src=10.8.0.15 dst=10.8.0.40 proto=tcp dport=8080 2026-10-04T14:05:01Z app login user=avery result=success src=10.8.0.20