Malicious PDF — malware analysis report

Static analysis result for SHA-256 445effc596145b09…

MALICIOUS

PDF

29.5 KB
MD5: aa3c241b757c3e0021a3acfaced330f2 SHA-1: dc2db1e0c328806f5043a8c234dd3d9e802ca759 SHA-256: 445effc596145b09e5bc172281a285d8ec585d5b9a3529e218d609639b2e6a3b
232 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and a Flash object, both of which are commonly used to exploit vulnerabilities. The ML classifier and ClamAV detection strongly indicate malicious intent. The embedded JavaScript stream, identified as 'javascript_obj0006_000.js', is highly suspicious and likely responsible for initiating the malicious activity, potentially downloading further stages.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 9

  • ClamAV: Pdf.Exploit.Agent-35955 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-35955
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • RichMedia (Flash) high PDF_RICHMEDIA
    PDF contains /RichMedia (Adobe Flash) which is a historic exploit vector
  • 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.
  • Embedded file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload
  • 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)
  • ASCII85Decode filter (with exploit indicators) low PDF_FILTER_85
    ASCII85 encoding filter present alongside exploit delivery indicators — uncommon outside of obfuscation
  • 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
20101297.swf
155cb1ff00e6c687a380ad31d1ca035be4d34d8d46179a65e733a7fef7b99805
pdf-embedded-file PDF EmbeddedFile object 16 at offset 0x9A1 53922 bytes
Detection
ClamAV: Pdf.Exploit.Agent-35955
Obfuscation or payload: unlikely
javascript_obj0006_000.js
0c1b2a30cbe8fe9d9401657c8972387afe3bb7fe682a8c414700b1db368d04b5
pdf-javascript-stream PDF /JS object 6 at offset 0xF6 9322 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 199 eval/decoder/string-building token(s).