Expanse
Expanse is a security scanner operated by Palo Alto Networks. It probes websites for vulnerabilities, exposed credentials, misconfigurations, or compliance issues.
Whether to allow it depends entirely on who is running it. If it is your own pen-test vendor or your bug-bounty researchers, allow it. If it is hostile reconnaissance, block it.
Look at the IP source and the request pattern. Hostile scanners tend to probe known-vulnerable URLs aggressively; legitimate scanners usually identify themselves and crawl gently.
See Expanse on your own site
Match the User-Agent header on incoming requests against the pattern below.
regex
For higher confidence, also verify the source IP against the operator's published ranges. UA strings can be spoofed; IP ownership is harder to fake.
Renders JavaScript
No
IP verification
User-Agent only
Crawl frequency
Variable / probing
Honors robots.txt
Yes
Honors Crawl-delay
Varies
The Palo Alto Networks bot family
See morePalo Alto Networks runs 2 bots in total. Each one is a separate user-agent so you can allow or block them independently.
Security Scanner
2- ExpanseYou are here
- Cortex Xpanse
Should I let Expanse through?
Watch your logs for a week first. Allow your own pen-testers and bug-bounty researchers. Block hostile reconnaissance. Source IP and pattern tell you which is which.
Does blocking Expanse affect my Google rankings?
No. Expanse is not a search-engine crawler. Your ranking on Google or Bing is unaffected by what you do here.
How do I confirm a request is really from Expanse?
Look at the User-Agent header in your access logs and match it against the strings listed above. Worth knowing that the User-Agent is easy to fake, so this check tells you "the traffic claims to be Expanse", not "the traffic is genuinely Expanse". If you need stronger guarantees, look for a reverse-DNS check or wait for Palo Alto Networks to publish IP ranges.
Is Expanse hostile traffic?
Depends entirely on the source. Penetration testers and bug-bounty researchers you've authorised should be allowed. Reconnaissance from random IPs probing for vulnerabilities should be blocked. The User-Agent alone doesn't tell you which is which, the source IP and request pattern do.
How is Expanse different from Palo Alto Networks's other bots?
Palo Alto Networks splits work across multiple user-agents so site owners can decide on each one independently. Training crawlers, live-fetch agents, search indexers, and agentic browsers each get their own name. Worth scanning the rest of the Palo Alto Networks family above to see which ones actually matter for your site.
What's the cleanest way to control Expanse?
Two layers. Robots.txt for the polite crawlers that read it, and rules at your CDN or edge for the ones that don't. Rankly's Agent Experience handles both from a single config, so you can allow, block, rate-limit, or serve a stripped-down version per bot. Agent Analytics handles the observation half so you know which bots are actually worth a rule.