What is 0xSI_f33d?
0xSI_f33d is a community-driven threat intelligence feed operated by SK-CERT (Slovak National CERT) and its partners. It aggregates malicious URLs, IP addresses, and domain indicators from Slovak internet monitoring, honeypot networks, and European security-sharing consortiums. Security vendors and ISPs across Europe pull from this feed to populate their blocklists automatically.
Why 0xSI_f33d flags legitimate domains
- Your domain or URL appeared in a phishing campaign observed by SK-CERT partners
- A compromised script or plugin served malicious content from your web server
- Your hosting IP block has historical association with flagged activity
- Automated crawlers detected a suspicious redirect chain on your site
- A former tenant of your IP address was responsible for malicious traffic
What a listing means for your business
A listing in 0xSI_f33d can propagate within 24 hours to dozens of downstream European security products, enterprise firewalls, and DNS filtering services, silently blocking your users without any warning.
How BrandsDefender gets you delisted
We verify that your domain is clean, prepare the evidence 0xSI_f33d needs, file the false positive dispute through the right channel and follow up until the flag is removed. No cure, no pay.
Frequently asked questions
How did 0xSI_f33d flag my domain?
0xSI_f33d ingests reports from automated honeypots, CERT incident response activity, and partner threat-sharing. A single phishing report mentioning your domain, even a false positive, is enough to trigger a listing.
Does 0xSI_f33d accept dispute submissions directly?
SK-CERT accepts dispute requests but processes them through internal review. Without a direct relationship and proper evidence packaging, submissions are frequently delayed or rejected. Our team has established the correct channels.