Malicious PDF — malware analysis report

Static analysis result for SHA-256 dfd8ef7667756ffb…

MALICIOUS

PDF

15.9 KB
MD5: e3150d4712204949213c61ae822f24aa SHA-1: 95294f6e432a3e55589c8e29056b8abe6b1634ae SHA-256: dfd8ef7667756ffb25176cbc288f679b905125e361758dcf90551f4d64f2b47c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell

The PDF contains heavily obfuscated JavaScript, flagged as a multi-stage dropper. This script is designed to evade analysis and likely downloads and executes a secondary payload. The ClamAV detection 'Pdf.Dropper.Agent-7314220-0' further confirms its malicious nature as a dropper.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 6

  • ClamAV: Pdf.Dropper.Agent-7314220-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Dropper.Agent-7314220-0
  • Obfuscated multi-stage PDF JavaScript dropper high PDF_JS_OBFUSCATED_DROPPER
    PDF JavaScript shows 3 independent signals of exploit-kit-style multi-stage obfuscation: annot_subject_stage, hex_dashed_payload, repeated_pluginschk. This is strongly consistent with pre-2011 Adobe Reader PDF droppers — OpenAction JS reads encoded data from annotation subjects, decodes it through one or more hex / base-N loops, and invokes eval indirectly (method name built one character at a time). The actual CVE is hidden in the final decoded layer and is not visible via static analysis.
  • 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.
  • syncAnnotScan annotation-staging primitive low PDF_FOXIT_SYNCANNOTSCAN
    PDF JavaScript calls syncAnnotScan() — a no-op annotation-enumeration primitive used by exploit-kit JavaScript to stage payload reads from annotation /Subject fields before eval(). Not a vulnerable sink itself; rarely seen in legitimate PDFs. (matched in decompressed 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0005_000.js
a3319192cac6d4dc4eeb6af2d736b0ffec979b23116a003bc7c23382761c32a5
pdf-javascript-stream PDF /JS object 5 at offset 0x148 733 bytes
legacy_pdfkit_stage_000.js
d2497f5de5d8924d8ab7db7de8dfbc3189a2424a647cd0fecb49ccabe55c6f25
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x1B0C 12513 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
deobfuscated.js
9edf352b0b62bf9277f2ddcdfd80dfd39ff52b706600d03ef3138ad9e7cc1644
deobfuscated-js PDF JavaScript deobfuscation pass 65401 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).