Malicious PDF — malware analysis report

Static analysis result for SHA-256 7eef68e3e35c3c9b…

MALICIOUS

PDF

118.4 KB
MD5: fe81d4df1c3f512b1188b62f8b862dd0 SHA-1: 2b296abf3e9bff7e105675ccd578cabb468597b8 SHA-256: 7eef68e3e35c3c9b2e5869f4e97bf58f1fc13b5db57e575b3b390108c5eff6ba
196 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious Link T1566.002 Spearphishing Attachment

The PDF contains embedded JavaScript, including calls to eval() and String.fromCharCode, which are commonly used for obfuscation and execution of malicious code. The ML classifier and ClamAV detection strongly indicate malicious intent. The primary attack pattern involves exploiting vulnerabilities within the PDF reader to download and execute additional malicious content, as suggested by the 'Agent' component in the ClamAV detection name.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

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
1d02681996cdb790c71db1b39a61f33b2b8700633b4e504e73ae70117b829607
pdf-javascript-stream PDF /JS object 6 at offset 0x143 626242 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).