It indicates that the domain uses an SSL certificate issued by a free or automated Certificate Authority, such as Let's Encrypt. While free SSLs are legitimate, they are frequently abused by threat actors due to their anonymity, ease of issuance, and short lifecycle.
Three questions every analyst asks before acting on this signal.
It indicates that the domain uses an SSL certificate issued by a free or automated Certificate Authority, such as Let's Encrypt. While free SSLs are legitimate, they are frequently abused by threat actors due to their anonymity, ease of issuance, and short lifecycle.
Because attackers can obtain them quickly and without identity verification, making it easier to establish HTTPS trust indicators on phishing or malware delivery sites. Their short renewal cycle also aligns with the short lifespan of malicious domains.
No. Many legitimate websites also use free SSLs for cost efficiency and automation. However, analysts should evaluate other contextual indicators — such as domain reputation, age, and category — before drawing conclusions.
A realistic shape of the entry the engine appends to the risk_signals array when this signal fires. Evidence keys are subgroup-default; per-signal overrides documented in the API reference.
{
"slug": "free_ssl_usage",
"name": "Free-Issued SSL Certificate",
"group": "http_crawling_history",
"subgroup": "ssl_behavior",
"direction": "malicious",
"evidence": {
"cert_issued_days_ago": 9,
"issuer": "letsencrypt",
"valid_for_days": 90,
"rotation_count_90d": 3,
"cert_type": "DV"
}
}15 other signals share the same subgroup. They detect related behaviors and often co-fire on the same IOC.
It means that the SSL/TLS certificate presented by the domain failed critical validation checks. This can occur due to m…
It means the SSL/TLS certificate’s Common Name (CN) or Subject Alternative Name (SAN) does not match the accessed domain…
It means the SSL/TLS certificate of the domain includes verified organizational details that have been authenticated by …
It means the domain is using an SSL/TLS certificate that was generated and signed by the same entity, without verificati…
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