Malicious PDF — malware analysis report

Static analysis result for SHA-256 aee709486d6542d1…

MALICIOUS

PDF

118.6 KB
MD5: 7b88aef483979153be43978b812e6742 SHA-1: 1b6ab357b164df21a9ea8ba157d3c26e4195ceb4 SHA-256: aee709486d6542d1a2d5a5371a6ff32b273f8357443f2281ac7c644339596e82
166 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript, which is heavily obfuscated and uses eval() and String.fromCharCode() functions. Heuristics indicate a large comment-padded JavaScript eval stager, suggesting it's designed to download and execute a second-stage payload. ClamAV detection as 'Pdf.Exploit.Agent-36086' further confirms its malicious nature. The primary IOC is the extracted JavaScript file.

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
303991a7bf9027bb5e52d6cf6b00178993fbf5ccfa559f3d921ad34d205f43b4
pdf-javascript-stream PDF /JS object 6 at offset 0x143 627163 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).