Malicious PDF — malware analysis report

Static analysis result for SHA-256 d455d03a4381e524…

MALICIOUS

PDF

15.7 KB
MD5: 2f9d95228b10a609da71505532170a37 SHA-1: 14baffe42a2dd52372e1d8f3d5b969bdc1dc0635 SHA-256: d455d03a4381e5248de555f26a0d7f2b604a7a678ce0198d3fa04a468829a0fd
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript T1204.002 Malicious File

The PDF file contains embedded JavaScript, with high-confidence heuristics indicating the use of eval() and a large comment-padded stager. ClamAV detection as 'Pdf.Exploit.Agent-36086' further supports malicious intent. The embedded JavaScript is likely responsible for downloading and executing a second-stage payload, a common technique for initial access.

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
4ac4ac3cee473c59d99d25d18b0a01993594abc98194b4bb013928f9efe11c55
pdf-javascript-stream PDF /JS object 6 at offset 0x143 426181 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
e83867e4ca886c4a07393a750ff0cd8723802d79b623236527c2bb4b8a1e512c
deobfuscated-js double percent-decoded annotation JavaScript at offset 0x143 262144 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 397 long base64-like blob(s).