Malicious PDF — malware analysis report

Static analysis result for SHA-256 f559a0fab5d30f4e…

MALICIOUS

PDF

21.3 KB
MD5: c9eecf3a0e5bfe59a7dbad4a24141c4c SHA-1: 86d2b90a6075530f074685ded138ceebb4f84936 SHA-256: f559a0fab5d30f4e672115578150f630f60ee5d196f7d665db0d599fa54fa01a
198 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript, indicated by multiple heuristic firings including PDF_JAVASCRIPT and PDF_JS. A critical heuristic identified the CVE-2009-4324 vulnerability related to media.newPlayer, suggesting the JavaScript is designed to exploit this flaw. The extracted JavaScript, particularly 'legacy_pdfkit_stage_000.js', appears to be obfuscated but is likely responsible for downloading and executing a second-stage payload. ClamAV detections further confirm the malicious nature of the file.

Heuristics 6

  • media.newPlayer — CVE-2009-4324 critical CVE exact CVE_2009_4324
    PDF JavaScript calls media.newPlayer — CVE-2009-4324 is a use-after-free in Adobe Reader's multimedia plugin triggered by media.newPlayer(). Actively exploited as a zero-day in December 2009. (identified after JavaScript deobfuscation)
  • ClamAV: Win.Trojan.Agent-36169 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Agent-36169
  • 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.
  • 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.
  • 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_obj0008_000.js
b7dc96c2e46656338d966d727b18c7cef9b2e66c7609db09e24ea79b6000b621
pdf-javascript-stream PDF /JS object 8 at offset 0x1E7 2019 bytes
Detection
ClamAV: Win.Trojan.Agent-36169
Obfuscation or payload: unlikely
legacy_pdfkit_stage_000.js
630bbd87d4c991442612bbfc5d0e64a58d98100212c3f8e897f80b45684ffd16
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x9FE 1262 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
legacy_pdfkit_stage_001.js
42025b552c7960b53abcd8cd732b01c8d109eccfdfefc352b9826c4d5807d414
deobfuscated-js cross-stage annotation API aliases at offset 0x1E7 81 bytes