Malicious PDF — malware analysis report

Static analysis result for SHA-256 d89f4c5a9a265c57…

MALICIOUS

PDF

118.5 KB
MD5: 2583659a4911288ee1907db322203d9d SHA-1: d340ffd69107ab125be7857325f6c7fc0562312b SHA-256: d89f4c5a9a265c577a92b7e2dbc56df95a75188db6ab3082913c38bcf8515068
166 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript, including a large comment-padded eval stager. This JavaScript is heavily obfuscated and uses eval() and String.fromCharCode(), indicating an attempt to hide malicious code execution. The ClamAV detection 'Pdf.Exploit.Agent-36086' further supports the malicious nature of the file, suggesting it exploits a known PDF vulnerability.

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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0006_000.js
dbf502e6dd740d288c2d9b2238b438a389b33ebeaf6d44d97952c66b341a0acc
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626444 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).
legacy_pdfkit_stage_000.js
ae7e33e4d59558a745be4784d1dad19c61505bed5d477a5ee33fadfcf8a0ac4f
deobfuscated-js double percent-decoded annotation JavaScript at offset 0x143 262144 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 655 long base64-like blob(s).