Malicious PDF — malware analysis report

Static analysis result for SHA-256 da482d517cb061b2…

MALICIOUS

PDF

118.7 KB
MD5: 2c9cfa597db648690a11d56202aa80be SHA-1: 16f61dd2a27e2cbcf95dbbcdcaabbdf04b68f586 SHA-256: da482d517cb061b263c691b0296fd3263a39277fc5ec751c01cc775f5c369a41
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript T1204.002 Malicious JavaScript

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including 'PDF_JAVASCRIPT', 'PDF_JS', and 'PDF_EVAL'. A high-severity heuristic 'PDF_JS_LARGE_COMMENT_PADDED_EVAL' suggests a stager designed to execute obfuscated JavaScript. ClamAV detection 'Pdf.Exploit.Agent-36086' further confirms its malicious nature. The presence of JavaScript and the nature of the heuristics strongly suggest the file is designed to exploit a vulnerability and download further malicious content.

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.

FilenameKindSourceSize
javascript_obj0006_000.js
6fcc4c791fa557e9a864164fff12ab0faa2f461f7ca78d9b3153ebc70ce6e37c
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627657 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
bc6f7d171bc59cc237ee5f50473a8cf957409976dac9fbd1a0b1646fa016a85e
deobfuscated-js double percent-decoded annotation JavaScript at offset 0x143 262144 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 610 long base64-like blob(s).