PDF malware analysis — malicious · 22b259735fa4b743

MALICIOUS

PDF

26.3 KB Created: 2011-72-51 03:25:00 Authoring application: String.fromCharCode

MD5: 191a8ec5f7b9fe381799646eb2fc678d SHA-1: 4fa7b32a615dcb7b87b88b892c7580adf5f6ad69 SHA-256: 22b259735fa4b7431d8b55f32997100010fa622fb283cfe03ac3f3f9195f3ee8

96 Risk Score

Malware Insights

MITRE ATT&CK

T1059.001 Command and Scripting Interpreter: PowerShell T1204.002 Malicious File: Malicious File

The PDF file contains embedded JavaScript, indicated by the PDF_JAVASCRIPT and PDF_JS heuristics. The JavaScript stream utilizes `eval()` and `String.fromCharCode`, suggesting obfuscation and dynamic code execution. The ML classifier strongly flags this PDF as malicious. The primary attack pattern involves leveraging these JavaScript capabilities to likely download and execute a second-stage payload, as evidenced by the extracted javascript_obj0001_000.js artifact.

Machine Learning

Nyx PDF Classifier malicious score 1.0000

Heuristics 5

eval() call high PDF_EVAL

eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
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.
String.fromCharCode low PDF_FROMCHARCODE

String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules.
Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE

One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 1

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`javascript_obj0001_000.js` `b6670868e6de1ca7999e2e2465f327be4192c5a8299264853996c3e499dc1873`	pdf-javascript-stream	PDF /JS object 1 at offset 0xA	1062 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 5 eval/decoder/string-building token(s).

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