Malicious PDF — malware analysis report

Static analysis result for SHA-256 59206611c38d6ff2…

MALICIOUS

PDF

53.2 KB Created: 2017-11-13 00:19:48 +01:00
MD5: cb33afd3aa39e5c201e19093accc8a21 SHA-1: e2a4c3a0b3a8dcc480de9eaaf6314b25d724fcbb SHA-256: 59206611c38d6ff2c1a1b857bbd82202e43c7b09d9d4598af9c350731cd20ea3
198 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by ClamAV with the signature 'Pdf.Dropper.Agent-7262860-0'. Static analysis revealed the presence of JavaScript with eval() calls and String.fromCharCode, indicating obfuscated code execution. The PDF also contains embedded scripts and embedded files, suggesting it acts as a dropper for further malicious activity. The primary function appears to be the execution of this embedded JavaScript, which likely downloads and executes a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9742

Heuristics 10

  • ClamAV: Pdf.Dropper.Agent-7262860-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Dropper.Agent-7262860-0
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • Embedded script payload in PDF stream medium PDF_EMBEDDED_SCRIPT_PAYLOAD
    PDF stream bytes contain an HTML/XFA <script> tag without accompanying Windows shell-execution primitives — common in accessible XFA forms but worth surfacing for analyst review.
  • 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
  • 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. (matched inside decoded stream)
  • 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. (matched inside decoded stream)
  • 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)
  • AcroForm button with action trigger low PDF_ACROFORM_BUTTON
    PDF contains a /Btn form field together with a SubmitForm/URI/Launch/JS trigger — this is the building block of fake 'Download' or 'Open' button overlays used in PDF phishing lures
  • 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://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://purl.org/dc/elements/1.1/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0029.bin
ddb2f0273ff53a78cba698afed0c23add8e219eaa85fecd99611493bebdb4d27		 pdf-embedded-file PDF EmbeddedFile object 29 at offset 0xC814 1237 bytes
objstm_0035_00.bin
eeb69e2dadfa00e86ba6af0e6cb511413051e5b08feb63db3edbb93a1dcfb2ad		 pdf-objstm-decoded PDF /ObjStm 35 0 obj (inflated) 1283 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.