Malicious PDF — malware analysis report

Static analysis result for SHA-256 a44bb6c63a1e5efb…

MALICIOUS

PDF

118.6 KB
MD5: 0d7168ba02030d7fe3bf7e9608a2f799 SHA-1: 3d5e5198b1297413542d3c934e3a595582f77706 SHA-256: a44bb6c63a1e5efb80460f8abe627ca8159acf83fc59fa2dae9ef7c0757231a4
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript

The PDF file contains multiple high-severity heuristic firings related to JavaScript execution, including eval() calls and a large comment-padded eval stager. ClamAV also detected it as 'Pdf.Exploit.Agent-36086'. The embedded JavaScript stream, named 'javascript_obj0006_000.js', is large and obfuscated, strongly suggesting it is designed to download and execute a second-stage payload. The exact nature of the payload cannot be determined due to obfuscation, but the overall pattern indicates a malicious 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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0006_000.js
e32bf157fc93014ec97d8abcde170100d041d9462f61ea920e3688fc3ee0c3af
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626779 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).