Qualys
Qualys security scanning
About this crawler
Qualys is a web crawler identified by the regular-expression pattern Qualys in the User-Agent request header. It is categorised as monitoring. Use the regex above to detect, log, allow, or block Qualys traffic in your web server, CDN edge rules, or robots.txt.
Block-rate · top 25k sites
No block-rate data for this crawler.
Technical details
- Name
- Qualys
- Pattern
Qualys- Tags
- monitoring
- Reference
- https://knownagents.com/agents/qualys
- Added
- 2026/04/26
- rDNS suffixes
.qualys.com- Instances
- 1 known sample(s)
rDNS verification (FCrDNS)
Verify a request is genuinely Qualys with forward-confirmed reverse DNS: the client IP's PTR record must end in one of the suffixes below and a forward A/AAAA lookup of that hostname must return the same IP. UA strings alone are spoofable; FCrDNS is not.
.qualys.com
Sample User-Agent strings
Mozilla/5.0 (compatible; Qualys; +https://www.qualys.com/)
Block this crawler
robots.txt — disallow Qualys:
User-agent: Qualys
Disallow: /
Apache .htaccess — return 403:
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} Qualys [NC]
RewriteRule .* - [F,L]
Nginx — return 403 inside a server block:
if ($http_user_agent ~* "Qualys") {
return 403;
}
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