Malicious PDF — malware analysis report

Static analysis result for SHA-256 b44a82a5ac4f621a…

MALICIOUS

PDF

118.5 KB
MD5: 49ff3b19db351147c0eccf3399a386f6 SHA-1: 7939c69a94aa4cafc4c4afda2178e3d1700e948b SHA-256: b44a82a5ac4f621a46ee2247a61e5a0ed5044df2fe39a3c0b2e19fdb0e0e54e4
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File

The PDF contains embedded JavaScript, including a heavily obfuscated 'eval' stager within a large comment. This pattern is typical for malware delivery, where the script attempts to download and execute a second-stage payload. The ClamAV detection 'Pdf.Exploit.Agent-36086' further confirms its malicious nature. Due to the obfuscation, the exact payload and delivery mechanism cannot be definitively determined, hence the 'unknown family' classification.

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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0006_000.js
2345f5be2f90a7d016fd1d7b50ca9658dbadeb08d394bda552101bd317ec375b
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626560 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).