The IT Pro’s Bookmark List: Free Cybersecurity Websites by Category

A quick-reference list of the free websites we use day to day in security and IT, grouped by job. Bookmark the lot, or just the sections you need.

Cyber news and research

• BleepingComputer: breaking security news, ransomware and patch coverage.
• The Hacker News: daily cybersecurity news and analysis.
• Infosecurity Magazine: industry news with a strong UK angle.
• Cyware: short daily threat briefings.
• Check Point Research: in-depth threat research and malware write-ups.

Threat intelligence and reputation

• VirusTotal: check files, URLs, domains, IPs and hashes against dozens of engines.
• Kaspersky Threat Intelligence Portal: reputation lookups for files, hashes, IPs and URLs.
• AlienVault OTX: community threat intel and indicator lookups (the successor to ThreatCrowd).
• AbuseIPDB: see whether an IP has been reported for attacks or abuse.
• IPVoid: IP blocklist checks plus handy network tools.
• GreyNoise Visualizer: is that IP targeting you, or just internet background noise?
• Cisco Talos Intelligence: IP, domain and email sender reputation.
• PhishTank: community database of known phishing sites.
• URLhaus: known malware distribution URLs.
• MalwareBazaar: search malware samples by hash.

Suspicious links and URLs

• urlscan.io: safely visit a URL and see the screenshot, redirects and requests. Use Unlisted for anything sensitive.
• Unshorten.It: reveal where a shortened link really goes.
• Redirect Detective: trace every hop in a redirect chain.
• ScanURL: quick phishing and malware check for a link.
• Wayback Machine: see what a site looked like in the past.

Malware sandboxes

• Hybrid Analysis: free automated sandbox powered by CrowdStrike Falcon.
• ANY.RUN: interactive sandbox. Free tier analyses are public.

DNS, IP and network

• DNSDumpster: map a domain’s DNS records and hosts.
• DNSlytics: domain, IP and hosting lookups, including reverse IP.
• crt.sh: find every certificate issued for a domain (great for spotting subdomains).
• Shodan: see what your public IPs expose to the internet.
• HackerTarget Online Nmap: scan your own perimeter from the outside.
• A-Packets: online PCAP viewer and analyser. Captures can hold sensitive data, so sanitise first.
• IANA Port Numbers: the official list of what each port is for.
• Wireshark OUI Lookup: identify a device’s manufacturer from its MAC address.

Email security

• MXToolbox: MX, SPF, DKIM, DMARC and blocklist checks.
• MXToolbox Email Header Analyzer: turn raw headers into a readable timeline.
• Microsoft Remote Connectivity Analyzer: test Exchange Online and Microsoft 365, and analyse message headers.
• NCSC Check your cyber security: free UK check of your domain’s email anti-spoofing set-up.
• Learn DMARC: send a test email and watch SPF, DKIM and DMARC being evaluated.

Website and TLS

• Security Headers: instant grade for a site’s HTTP security headers.
• Qualys SSL Labs: deep TLS and certificate test.
• MDN HTTP Observatory: Mozilla’s header scanner with fix-it advice.

Vulnerabilities

• CVE.org: search the official CVE records.
• CISA Known Exploited Vulnerabilities: CVEs exploited in the wild. Patch these first.
• FIRST EPSS: how likely a CVE is to be exploited in the next 30 days.

Breaches, warnings and reporting (UK)

• Have I Been Pwned: check addresses, or your whole domain, against known breaches.
• NCSC Early Warning: free alerts about threats to your organisation’s IPs and domains.
• NCSC Report a scam website: get scam sites taken down. Forward phishing emails to [email protected].

Everyday utilities

• CyberChef: GCHQ’s decode-anything toolkit. Runs in your browser.
• regex101: build and test regular expressions.
• explainshell: break down what a command line does.
• LastPass Password Generator: quick strong passwords and passphrases.
• RouterPasswords.com: default device credentials. Check your kit is not still using them.

Tools worth downloading

• Windows Sysinternals: Process Explorer, Autoruns, Procmon and more from Microsoft.
• Metasploit: penetration testing framework, for authorised testing only.
• SecLists: wordlists and payloads for security testing.

Frameworks, standards and guidance

• MITRE ATT&CK: the reference catalogue of attacker techniques.
• ATT&CK Navigator: map your detections and coverage against ATT&CK.
• The Pyramid of Pain: why some indicators hurt attackers more than others.
• CIS Benchmarks: free hardening guides for operating systems, cloud and apps.
• NCSC Advice and Guidance: UK government guidance on every security topic.
• ICO AI and Data Protection Risk Toolkit: assess data protection risks in AI projects.
• PLOT4AI: threat modelling cards for AI systems.
• GDPR Enforcement Tracker: every published GDPR fine, searchable.

Live attack maps

• Check Point Live Cyber Threat Map: real-time view of attacks seen by Check Point.
• Kaspersky Cybermap: global threat activity in 3D. Great for wallboards and presentations.

Got a site you cannot work without? Tell us through our contact page and we will add it.