Quick & Dirty Obfuscated JavaScript Analysis, (Sun, Nov 24th)

[Quick -& Dirty Obfuscated JavaScript Analysis](/forums/diary/Quick+Dirty+Obfuscated+JavaScript+Analysis/31468/)================================================================================================================* * [](http://www.facebook.com/sharer.php?u=https%3A%2F%2Fisc.sans.edu%2Fforums%2Fdiary%2F31468 ‘Share on Facebook’)* [](http://twitter.com/share?text=Quick%20%26%20Dirty%20Obfuscated%20JavaScript%20Analysis&url=https%3A%2F%2Fisc.sans.edu%2Fforums%2Fdiary%2F31468&via=SANS_ISC ‘Share on Twitter’) **Published** : 2024-11-24. **Last Updated** : 2024-11-24 09:22:41 UTC **by** [Didier Stevens](/handler_list.html#didier-stevens) (Version: 1) [0 comment(s)](/diary/Quick+Dirty+Obfuscated+JavaScript+Analysis/31468/#comments) As mentioned in diary entry ‘[Increase In Phishing SVG Attachments](https://isc.sans.edu/diary/Increase%20In%20Phishing%20SVG%20Attachments/31456)’, I have a [phishing SVG sample with heavily obfuscated JavaScript](https://www.virustotal.com/gui/file/953d83642b6aae079afd82a6270651bd073ec1cdf5a3e97e05b98619f4257593).![](https://isc.sans.edu/diaryimages/images/20241124-095202.png)As I didn’t want to spend time doing static analysis, I did a quick dynamic analysis instead. TL;DR: I open the SVG file in a VM disconnected from the Internet, and use Edge’s developer tools to view the deobuscated URL.First I make sure the VM is disconnected from the network:![](https://isc.sans.edu/diaryimages/images/20241124-091029.png)Then I open the SVG file in Edge (Chrome works too):![](https://isc.sans.edu/diaryimages/images/20241124-091126.png)I open the developer tools:![](https://isc.sans.edu/diaryimages/images/20241124-091149.png)I switch to the Network tab:![](https://isc.sans.edu/diaryimages/images/20241124-091211.png)And then I type a dummy password and click on the Download button:![](https://isc.sans.edu/diaryimages/images/20241124-091235.png)I can then view the deobfuscated URL:![](https://isc.sans.edu/diaryimages/images/20241124-091321.png)And also the payload:![](https://isc.sans.edu/diaryimages/images/20241124-091340.png)Didier Stevens Senior handler [blog.DidierStevens.com](http://blog.DidierStevens.com) Keywords:[0 comment(s)](/diary/Quick+Dirty+Obfuscated+JavaScript+Analysis/31468/#comments)

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