Danni's DNS List - The most comprehensive single page list of public DNS info you will find on the entire internet.
Central Ops - Advanced online internet utilities.
VirusTotal - Analyse suspicious files, domains, IPs and URLs to detect malware and other breaches, automatically share them with the security community.
DNSChecker - 80+ analysis tools for the web.
Dig - Google Admin Toolbox's version of the "dig" command, showing DNS record details of IPs and Domains.
Jotti's Malware Scanner - Upload files up to 250mb to scan for malware against 14 malware detection databases at the same time.
ICANN Lookup - The most legit source for registrant data of websites. Essentially the same as a WhoIs lookup.
W3Schools - Tutorials to learn basic coding in any commonly used programming language.
OldVersion.com - "Newer is not Always Better" Repository of old (and new-ish) software downloads for Windows, Mac, Linux, and Android.
Internet Archives - Their "Wayback Machine" is a database with snapshots of websites at different points in a domain's history.
Free Proxy - A huge list of proxy servers to run your internet connection through. Adds a hoop for spyware to jump through; otherwise unnecessary.
ProxySite - Open a website using one of their servers if you're unsure if you're looking at the real thing or a DNS-spoofed copy.
Denial of Service Attacks
Phishing
DNS Poisoning
Man-in-the-Middle
Future Threat: Quantum Computing
Pegasus (the first well-known software to spy on ANYONE)
Buy a Phone Hard-Coded with Spyware