Malicious PDF — malware analysis report

Static analysis result for SHA-256 d6879bbe5f1ca70c…

MALICIOUS

PDF

15.7 KB
MD5: 2e90892b1d77e484f21419e7fed3e857 SHA-1: 9833a1505c2ec66a8f6f6414e6d0ecf745288acd SHA-256: d6879bbe5f1ca70c8bcf6dff2c4d06b0fcb0721d75ec0817838f6e2a7a9f9223
166 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT, PDF_JS, and PDF_EVAL. A high-confidence heuristic, PDF_JS_LARGE_COMMENT_PADDED_EVAL, specifically points to a JavaScript eval stager. The ClamAV detection of 'Pdf.Exploit.Agent-36086' further confirms its malicious nature. The embedded JavaScript is likely responsible for downloading and executing a second-stage payload, although the exact mechanism is obfuscated.

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
e2a0e83ab75a2714a7677847367b1a64d85c0ddb06a00a3f77dad0aad44416a9
pdf-javascript-stream PDF /JS object 6 at offset 0x143 425566 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).