The Karen IT Domain Blocklist (DBL) is a continuously updated feed of malicious domains — phishing infrastructure, malware distribution and command-and-control servers — maintained by Karen IT's threat intelligence and investigation teams.
Before a user reaches a phishing page, before malware calls home, before a brand impersonation site loads — the domain has to resolve. DNS is the first step in every internet interaction, which makes it the most efficient point at which to block malicious activity.
The Karen IT DBL is built from active investigation — not aggregated from public feeds. Every entry has been reviewed and verified against multiple data sources before it is added. This is what keeps coverage comprehensive and false positives low.
New threats are added in near real-time as our investigation and intelligence teams identify them. When a phishing campaign launches, the infrastructure is blocked before most users encounter it — not after the first reports arrive.
A blocklist that generates false positives gets removed from production environments. Our curation process maintains coverage without blocking legitimate traffic — suitable for deployment in public DNS resolvers like Quad9 at massive scale.
Most domain blocklists pull from public threat feeds, apply automated filters, and publish the result. This produces broad coverage but also produces noise: false positives, stale entries, and gaps where novel threats have not yet appeared in any public feed. The Karen IT DBL is built differently — from active investigation of malicious infrastructure.
Every domain in the Karen IT DBL has been reviewed by our threat intelligence team. Each entry is verified against our CTI platform's scan data, WHOIS records, passive DNS, certificate transparency logs, and hosting intelligence before being classified and added. A domain that looks malicious by name but resolves to a legitimate service will not enter our blocklist.
Our investigation teams actively track phishing campaigns and malware operations as they unfold. When a new campaign is identified — through KSRC report intake, our CTI platform, URLAbuse feeds, or direct investigation — the associated domains are assessed and added in near real-time. We do not wait for public reporting cycles.
Threat actors rarely register single domains — they register clusters. Our Domain Hunting capability identifies these clusters, which means when a new campaign is detected, we investigate the full infrastructure footprint and add it entirely, substantially reducing the window between a campaign launching and full blocking.
A blocklist is only as useful as its false positive rate. Our curation process maintains coverage without blocking legitimate traffic — designed for environments like Quad9, where a single false positive affects millions of users. Stale entries are periodically reviewed and removed.
Quad9 is one of the world's largest privacy-focused public DNS resolvers, handling billions of DNS queries every day. Quad9's threat blocking infrastructure draws from a curated set of vetted threat intelligence providers — and the Karen IT DBL is among them.
This is a production deployment in one of the most demanding DNS environments in the world. A blocklist that performs in the Quad9 environment — where false positives affect millions of users, where update latency affects real threat coverage, and where data quality is continuously monitored — has demonstrated real-world operational quality.
About Quad9: Quad9 operates as a free, privacy-first public DNS resolver at 9.9.9.9. It blocks access to malicious domains by consulting a set of vetted threat intelligence feeds at query time. The Karen IT DBL contributes to this blocking capability. For more, visit quad9.net.
The Karen IT DBL is publicly queryable at dbl.urlabuse.com. Check any domain — for free, with no registration — using three different methods.
The simplest option. Enter the domain you want to check and get an immediate result. No account, no API key, no setup required.
dbl.urlabuse.com →Query the DBL directly via DNS. Prepend the domain you want to check to our nameserver address and send an A record query.
Nameserverdbl.urlabuse.comdig A malware.wicar.org.dbl.urlabuse.com @dbl.urlabuse.com
For automated lookups without DNS infrastructure. No authentication required for individual queries. The only parameter is rd — the domain or FQDN you want to check.
https://dbl.urlabuse.com/lookup?rd={domain}
import requests, json
r = requests.get(
"https://dbl.urlabuse.com/lookup",
params={"rd": "malware.wicar.org"},
timeout=3
) print(json.loads(r.text))
curl "https://dbl.urlabuse.com/lookup?rd=malware.wicar.org"
Our blocklist covers the full range of malicious domain use cases our investigation and intelligence teams encounter in active operations.
Domains actively serving phishing pages targeting financial institutions, e-commerce platforms, technology companies, government services, and individual users — credential harvesting pages, fake login portals, and social engineering landing pages.
Domains used to host, distribute, or deliver malware payloads — including drive-by download sites, payload staging servers, and domains used in malspam campaigns to deliver documents with embedded malicious content.
Domains serving as command-and-control infrastructure for malware — receiving stolen data, delivering instructions to infected hosts, facilitating botnet operation. C2 blocking at DNS level neutralizes active infections before endpoint remediation is required.
Domains registered to impersonate legitimate brands through typosquatting, homograph attacks, or addition of brand names to unrelated TLDs — typically used for phishing, fraud, or traffic interception targeting users who trust the impersonated brand.
Domains associated with online fraud: fake investment platforms, advance-fee fraud, tech support scams, parcel delivery fraud, and other schemes designed to defraud users through deceptive websites.
Domains registered specifically for malicious purposes, identified through our daily domain monitoring and Domain Hunting — often before they appear in any public threat feed. Early detection is where our investigation-backed approach provides the most distinctive coverage.
The Karen IT DBL integrates cleanly into DNS resolver and security platform environments. Updated continuously, with entries added in near real-time for high-priority threats.
| Feed format | Domain listRPZ available |
| Nameserver | dbl.urlabuse.com |
| Public lookup | dbl.urlabuse.com — web · DNS · API · no account required |
| Update frequency | Continuous — near real-time for high-priority threats |
| Coverage | Phishing · Malware · C2 · Newly registered malicious domains |
| False positive rate | Reviewed and minimized — suitable for production DNS resolver deployments |
| Historical data | Available to authorized integrators |
| API access | Public: dbl.urlabuse.com/lookup · Full feed: by request |
| Access model | Public lookup: open · Full feed: vetted organizations only |
The Karen IT DBL is designed for organizations where data quality, false positive rates, and update speed are operationally significant.
DNS resolvers offering security filtering to end users — like Quad9 — require blocklist data that is both comprehensive and precise. A false positive in a public resolver affects all users who query that domain. Our curation process is designed with this constraint in mind.
Organizations deploying DNS-layer security for their own networks benefit from feeds that cover the threats their sector is targeted by, with update speeds that match threat actor operational tempo.
Internet service providers and mobile carriers offering security filtering to subscribers require blocklist data at scale. The Karen IT DBL is structured to meet the performance and format requirements of large-scale resolver deployments.
Security products incorporating DNS-layer threat blocking — endpoint platforms, secure web gateways, SASE, and DNS security services — require reliable, continuously updated threat intelligence feeds. The Karen IT DBL is available for product integration by vetted vendors.
Organizations consuming threat feeds for SIEM enrichment, indicator correlation, and threat hunting benefit from a domain blocklist that carries investigation context — not just a list of domains, but classification data that enables more precise analysis.
Registrars and registries proactively suspending malicious domains use blocklist data to identify domains requiring review. Our investigation-backed entries carry evidentiary context needed to support suspension decisions — not just a flag, but documented reasoning.
Two levels of access — designed for different use cases.
Available to anyone at dbl.urlabuse.com — no registration, no account, no rate limit on individual queries. Check any domain, any time, for free. Available via web interface, DNS query, or HTTP API.
Access to the full DBL feed — for integration into DNS resolvers, security products, or threat intelligence platforms — is provided to vetted organizations with a legitimate security or infrastructure use case. Requests are reviewed individually.
The Karen IT DBL draws its strength from multiple independent detection pipelines — each adding coverage the others alone would not provide.
Community URL reporting and blacklisting. Confirmed malicious URLs flow into the DBL after verification.
urlabuse.com →Internal threat intelligence platform. Domains from active scanning and domain hunting are assessed for DBL inclusion.
Learn more →Security Response Center. Domains identified through active case handling are reviewed and added where confirmed malicious.
ksrc.karenit.net →Phishing kit repository. Confirmed kit deployment domains enter the DBL with full infrastructure context from kit analysis.
Learn more →DNS is the first step in every internet interaction — and the most efficient point at which to stop threats before they reach your users, your network, or your customers. For anyone who wants to check a single domain, it's free and instant. For organizations that want to integrate the full feed, contact us.