Malicious PDF — malware analysis report

Static analysis result for SHA-256 ce7a7c77f5a61cb0…

MALICIOUS

PDF

15.7 KB
MD5: 3a37d144d0d62ad8807096f438b99b27 SHA-1: 85bdf417fe6bf04158b927939f67019b2aed5523 SHA-256: ce7a7c77f5a61cb057fe4c43f98177418894bed0d5857f6d8445416202eff51e
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF contains embedded JavaScript, including a large comment-padded eval stager, which is a common technique for obfuscating malicious code. The presence of `eval()` and `String.fromCharCode` further indicates code execution. ClamAV detection as 'Pdf.Exploit.Agent-36086' strongly suggests an exploit is present. The primary attack pattern involves exploiting a vulnerability within the PDF reader to execute arbitrary code, likely to download and run a second-stage payload.

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
ab80d9aec6403f6588ee8ea1486dbbf44be450c17a677744d6c76eaeb2b32a1b
pdf-javascript-stream PDF /JS object 6 at offset 0x143 425484 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).