Malicious PDF — malware analysis report

Static analysis result for SHA-256 f08a74fa07b42a6c…

MALICIOUS

PDF

118.5 KB
MD5: 87c299ddeb7c32cd363a43acca679b04 SHA-1: 2d0c534bb49f0297ef3b7b6ce4ebac9e798a76d0 SHA-256: f08a74fa07b42a6c8acefdd7f4c1cb7cc5132fb84bd76fbb4ff5ce3596ccc496
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1059.007 JavaScript

The PDF contains embedded JavaScript, including a large comment-padded eval stager, indicating an attempt to obfuscate and execute malicious code. The presence of `eval()` and `String.fromCharCode` further supports this. ClamAV detection as 'Pdf.Exploit.Agent-36086' confirms its malicious nature. The specific exploit or payload is not clearly discernible due to obfuscation, but the general pattern suggests an exploit delivery mechanism.

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
49411425133b2e2a24598d012de00950746a1bf58674866ffc1d44fc46c1ba42
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627268 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
d1fce21b3cf34fe85a552bad17e18a1bf1586afdae243ef4d8b83d9aaf7c529e
deobfuscated-js double percent-decoded annotation JavaScript at offset 0x143 262144 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 629 long base64-like blob(s).