Malicious PDF — malware analysis report

Static analysis result for SHA-256 c89407ad53041c21…

MALICIOUS

PDF

118.5 KB
MD5: 86c6d27ef513e757e12786bc911155e0 SHA-1: fc3fea591775079b94f43ac2c43a1ca82a2dac52 SHA-256: c89407ad53041c21be548f8431f7afd524a91de0abd33d164c9391953a1aa14d
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'. The 'PDF_JS_LARGE_COMMENT_PADDED_EVAL' heuristic suggests a stager pattern. ClamAV detection as 'Pdf.Exploit.Agent-36086' strongly indicates malicious intent, likely involving the execution of a second-stage payload via the JavaScript. The document body is unreadable, but the presence of obfuscated JavaScript and the ClamAV signature point to an 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0006_000.js
3abd6c0890cce9fb75a8ea4d9e6fb83c3d857a6f0ffbbe1fe6515535f20ed082
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626573 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
14d0acfb553c209854fbf86c178a57e99810d90a0e6a42bc9392e22373d119fa
deobfuscated-js double percent-decoded annotation JavaScript at offset 0x143 262118 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 639 long base64-like blob(s).