Folks often like to think of URLs as an entity that can be evaluated: “Is it harmless, or is it malicious?” In particular, vendors of security products tend to lump URLs in with other IoCs (indicators of compromise) like the hash of a known-malicious file, a malicious/compromised digital certificate, or a known-malicious IP address. Unfortunately,Continue reading “Beware: URLs are Pointers to Mutable Entities”
Tag Archives: security
Security Tradeoffs: Privacy
In a recent post, I explored some of the tradeoffs engineers must make when evaluating the security properties of a given design. In this post, we explore an interesting tradeoff between Security and Privacy in the analysis of web traffic. Many different security features and products attempt to protect web browsers from malicious sites byContinue reading “Security Tradeoffs: Privacy”
Security: Tradeoffs
Absolute security is simple– put your PC in a well-guarded vault, and never power it on. But that’s not what PCs are built for, and good luck finding a job that would pay you for such advice. Security Engineering (like all engineering) is a story of tradeoffs. Tradeoffs commonly take place across multiple dimensions: AsContinue reading “Security: Tradeoffs”
The Challenge of IP Reputation
When protecting clients and servers against network-based threats, it’s tempting to consider the peer’s network address when deciding whether that peer is trustworthy. Unfortunately, while IP addresses can be a valuable signal, attempts to treat traffic as trustworthy or untrustworthy based on IP address alone can be very prone to mistakes. Background Most clients andContinue reading “The Challenge of IP Reputation”
Defensive Techniques: Application Guard
Earlier this year, I mentioned that I load every phishing URL I’m sent to see what it does and whether it tries to use any interesting new techniques. While Edge’s “Enhanced Security Mode” reduces the risks of 0-day attacks against the browser itself, another great defense available for enterprise users is Microsoft Defender Application Guard.Continue reading “Defensive Techniques: Application Guard”
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