URLs
*VirusTotal - will give a reputation.
Google Safe Browsing - will tell if it’s on a blacklist
urlscan - best and quickest, it will flag if they are active phishing, will give a screenshot, and has an awesome API.
(NOTE) If you detect any as malicious, block them on your firewalls and do a search across your logs.
*Can scan files
IPs
CyberChef - Decoder
Email Header Analyzer - Analyze email headers
Blockchain Explorer - Track blockchain activities
Attachments
Check the hash of the attachments. If it’s there, check the reputation, if it’s not, upload the file and scan analyze it privately in a sandbox
VirusTotal - will give a reputation.