Malicious PDF — malware analysis report

Static analysis result for SHA-256 31dc747b16d8861f…

MALICIOUS

PDF

35.2 KB
MD5: 554dfb1049fdba6edcc7b0121a3f0bd7 SHA-1: 2133b6da9d138991a00ec71bb5f285cfddce3233 SHA-256: 31dc747b16d8861f0fcd5066a0a69ffc50ea92b34d06d7e5a11708dcfc229979
102 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript and a RichMedia (Flash) object, indicating an attempt to exploit vulnerabilities. The presence of `String.fromCharCode` and ASCIIHexDecode filters further suggests obfuscation and potential exploit code. The embedded JavaScript stream, `javascript_obj0006_000.js`, is likely responsible for executing the malicious payload, possibly by downloading additional content or establishing a connection. The embedded file `embedded_file_obj0016.bin` may be the secondary payload.

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
embedded_file_obj0016.bin
8f9c84c8c00bc62ae296a81fac6640aa852ea67548abc1bd639aa0da1a1696c4
pdf-embedded-file PDF EmbeddedFile object 16 at offset 0xE2D 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
785ddb4ad9ead3d606eb30174fa5a388e292ecfd35907538d7315a8c2e52d4ab
pdf-javascript-stream PDF /JS object 6 at offset 0x105 10470 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).