Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac854220e2ea7cb8…

MALICIOUS

PDF

35.2 KB
MD5: 0d483a1dfb9d4b5c1ea0a7c1bbeb773b SHA-1: bcc07007414c025dcc31706486c3974ee53c2fb3 SHA-256: ac854220e2ea7cb8b673d478398fe9b6b40486dc9dd98a46fa9455d059f201fa
132 Risk Score

Malware Insights

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

The PDF file exhibits multiple indicators of malicious intent, including embedded JavaScript and a Flash object (Adobe.swf). The presence of JavaScript, particularly using `String.fromCharCode` and potentially obfuscated streams, suggests an attempt to execute arbitrary code. The ML classifier strongly flags this PDF as malicious. The embedded Flash object further increases the likelihood of exploit delivery. The extracted artifacts, 'Adobe.swf' and 'javascript_obj0006_000.js', are direct evidence of the malicious components.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 9

  • RichMedia (Flash) high PDF_RICHMEDIA
    PDF contains /RichMedia (Adobe Flash) which is a historic exploit vector
  • ASCIIHexDecode filter (with exploit indicators) medium PDF_FILTER_HEX
    Hex-encoding filter present alongside exploit delivery indicators — often used to hide payload or shellcode bytes
  • 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
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic
  • 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.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://ns.adobe.com/xdp/
    • http://www.xfa.org/schema/xci/2.6/
    • http://www.xfa.org/schema/xfa-template/2.6/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
Adobe.swf
8f9c84c8c00bc62ae296a81fac6640aa852ea67548abc1bd639aa0da1a1696c4
pdf-embedded-file PDF EmbeddedFile object 16 at offset 0xE53 27347 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.99, consistent with packed or encrypted content.
javascript_obj0006_000.js
1077af6994d49177c80ebca50b38a1e6b709db1c7b4dbb2d6f890aed892e7113
pdf-javascript-stream PDF /JS object 6 at offset 0x105 10512 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).