PDF malware analysis — malicious · 1553c5ea5940c8e6

MALICIOUS

PDF

4.5 KB Authoring application: Vabameuaki

MD5: 5345b85e56895aa64fb5be2f664ddd0c SHA-1: 75ddcb5691ac14c0a44fafe0e638eea50e0b4074 SHA-256: 1553c5ea5940c8e63ff1b4330f6169c999f5fbc31648d04e906acdc491f834ab

86 Risk Score

Malware Insights

MITRE ATT&CK

T1059.007 JavaScript T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript that is obfuscated using XOR and string concatenation. The script reconstructs and executes a payload, likely a downloader, based on the heuristic 'PDF_PAGE_WORD_XOR_EVAL_STAGER'. The ML classifier strongly indicates maliciousness. The initial access vector is inferred as Spearphishing Attachment due to the nature of PDF malware.

Machine Learning

Nyx PDF Classifier malicious score 1.0000

Heuristics 3

Page-word XOR JavaScript eval stager high PDF_PAGE_WORD_XOR_EVAL_STAGER

PDF JavaScript enumerates rendered page words with getPageNthWord/getPageNumWords, extracts encoded byte fragments, XOR-decodes the stage with char-code helpers, and evals the result. This is an old exploit-kit staging pattern and is not normal document JavaScript.
JavaScript action low PDF_JAVASCRIPT

PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
Embedded JS stream low PDF_JS

PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.

Extracted artifacts 1

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`javascript_obj0011_000.js` `1ec398366107a5fedd9bcf18a57f32d68d58e87986c8ad1c876f457b209e2152`	pdf-javascript-stream	PDF /JS object 11 at offset 0xCA2	815 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.