PDF malware analysis — malicious · ef94daafa9cbd85c

MALICIOUS

PDF

15.7 KB

MD5: 158e47620a4fe5114593e1f66207ff24 SHA-1: 543e9d21bb2e635d945b8452e61ec8c350de57e7 SHA-256: ef94daafa9cbd85c3656b55ffc8191150efae807cc35650c0a007ce049ffd159

166 Risk Score

Malware Insights

MITRE ATT&CK

T1059.001 PowerShell T1204.002 Malicious File

The PDF file contains multiple heuristics indicating JavaScript execution, including `PDF_JAVASCRIPT`, `PDF_JS`, and critically, `PDF_JS_LARGE_COMMENT_PADDED_EVAL`. The presence of `eval()` and `String.fromCharCode` suggests obfuscated code. The ClamAV detection `Pdf.Exploit.Agent-36086` further confirms its malicious nature. The embedded JavaScript streams, particularly the deobfuscated one, likely contain logic to download and execute further stages, although the exact payload URL or execution method is not directly extractable from the provided evidence.

Heuristics 7

ClamAV: Pdf.Exploit.Agent-36086 critical CLAMAV_DETECTION

ClamAV detected this file as malware: Pdf.Exploit.Agent-36086
eval() call high PDF_EVAL

eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
Large comment-padded JavaScript eval stager high PDF_JS_LARGE_COMMENT_PADDED_EVAL

PDF JavaScript contains a very large stream padded with long random-looking block comments around String.fromCharCode and eval. This is an exploit-kit obfuscation shape used to bury a decoder and recovered stage inside noise, not normal PDF form automation.
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. (matched inside decoded stream)
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 2

Files carved from inside the sample during analysis.

Filename	Kind	Source	Size
`javascript_obj0006_000.js` `667738d1c1973bc4f1127b0127ff8ce977e9167a7eda53509cc54ea815552cdd`	pdf-javascript-stream	PDF /JS object 6 at offset 0x143	424336 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 42 long base64-like blob(s).
`legacy_pdfkit_stage_000.js` `8b3f8f3d4a085e5f1673c2dece1561eee70cc0079cf5225e501b830b648f8e6a`	deobfuscated-js	double percent-decoded annotation JavaScript at offset 0x143	262144 bytes
Detection ClamAV: No threats found Obfuscation or payload: likely Carved artifact contains 667 long base64-like blob(s).

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