isMalicious + Spamhaus
DNS blocklists and threat data. isMalicious consumes this source and correlates it with others — this page explains what that adds, and when to go to the source directly.
Spamhaus is one of the sources isMalicious aggregates
We are not a replacement for Spamhaus, and the table below is not a scoreboard. isMalicious ingests or queries Spamhaus alongside other sources and returns a single weighted verdict. Rows where isMalicious shows a capability Spamhaus does not are usually capabilities of the aggregation layer, not evidence that our data on Spamhaus's own specialty is better. For Spamhaus's primary use case, go to Spamhaus.
Quick verdict
Choose Spamhaus for proven DNS blocklists at the mail gateway or DNS layer. Choose isMalicious for API-first multi-indicator threat intelligence, enrichment, STIX/TAXII, and CVE/ransomware context beyond DNSBL lookups.
isMalicious
Real-time threat intelligence API with multi-source correlation, CVE intelligence, and ransomware leak-site tracking.
Best for: Automated threat intelligence at scale
Spamhaus
Spamhaus operates widely used DNS blocklists (DROP, EDROP, SBL) for spam and malicious IP blocking. It is authoritative for email and network blocking but is not a full threat intelligence platform with enrichment APIs, CVE data, or multi-indicator correlation.
Best for: DNS blocklist (DNSBL) email and network filtering
Feature Comparison
| Feature | isMalicious | Spamhaus |
|---|---|---|
| IP blocklist / DNSBL | ||
| REST reputation API | Partial | |
| Domain reputation API | Partial | |
| URL scanner | ||
| Multi-source confidence scoring | ||
| STIX/TAXII export | Partial | |
| Ransomware leak-site tracking | ||
| CVE intelligence (CVSS, EPSS, KEV) | ||
| Bulk API (1K+ indicators) | Limited | |
| Free tier available | Partial |
Every row above is backed by live data — see it on your own indicators.
Run a free reportSpamhaus — Strengths & Limitations
- Industry-standard DNS blocklists
- Strong spam and botnet IP coverage
- DROP/EDROP for firewall import
- Long track record
- DNSBL model — not a REST enrichment API
- Limited domain/URL/hash API surface
- No CVE, EPSS, or KEV intelligence
- No ransomware group tracking
- Commercial licensing for high-volume use
- No unified report page for analysts
Pricing
Spamhaus
Free for low volume; commercial datafeed licensing for production
Frequently Asked Questions
Can isMalicious replace Spamhaus DROP?
Many teams use both: Spamhaus DROP for DNS-layer blocking and isMalicious for API enrichment, STIX/TAXII feeds, domain/URL/hash reputation, and analyst workflows. isMalicious TXT blocklists can complement DROP imports.
Does isMalicious use Spamhaus data?
isMalicious aggregates reputation signals from multiple feeds including Spamhaus-class blocklist sources, combined with other providers and confidence weighting.
Which is better for email security teams?
Spamhaus remains the standard for DNSBL at the MTA. isMalicious adds pre-delivery URL/domain checks, enrichment in SIEM, and broader threat context beyond IP DNSBL alone.
Other Comparisons
Decide with your own data
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