How to Read JavaScript That Was Written Not to Be Read

Fri, 13 Nov 2026 00:00:00 +0000

Open the source of a phishing page, a malicious ad or a skimmer, and you’ll often find a wall of JavaScript that looks like someone fell asleep on the keyboard. Variable names like _0x3c1e. Strings that make no sense. One line that scrolls for a minute.

That’s obfuscation. The author wants the code to run, but not to be read.

You don’t need to understand every line. You need to answer two questions: what does this script do, and who does it talk to? Most obfuscation is a stack of simple tricks you can peel off one layer at a time.

Malware-Analysis on Suspicious Bytes

How to Read JavaScript That Was Written Not to Be Read