Malicious PDF — malware analysis report

Static analysis result for SHA-256 b42e32f5ce9729cc…

MALICIOUS

PDF

6.6 KB
MD5: 19bcb87dab0e36d60705465c112b2859 SHA-1: 08204f772514724f79746462f089138333cd5e2d SHA-256: b42e32f5ce9729cc13f169800e7e39b7a6c45793072b52431c310888998e0da0
266 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File T1071.001 Web Protocols

The PDF file contains multiple critical heuristic firings indicating exploitation of CVE-2009-4324, CVE-2009-0927, and CVE-2007-5659. These vulnerabilities are used to execute obfuscated JavaScript. The embedded JavaScript streams, identified as 'javascript_obj0039_000.js', 'legacy_pdfkit_stage_000.js', and 'legacy_pdfkit_stage_001.js', are likely responsible for downloading and executing a second-stage payload, as indicated by the ClamAV detection 'Js.Exploit.Shellcode-18'. The lack of readable document body text prevents a more specific determination of the lure, but the technical indicators strongly suggest a malicious exploit delivery.

Heuristics 8

  • 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)
  • Collab.getIcon — CVE-2009-0927 critical CVE exact CVE_2009_0927
    PDF JavaScript calls Collab.getIcon — CVE-2009-0927 is a stack buffer overflow in Adobe Reader triggered by Collab.getIcon() with a crafted argument. Allows arbitrary code execution. (identified after JavaScript deobfuscation)
  • Collab.collectEmailInfo — CVE-2007-5659 critical CVE exact CVE_2007_5659
    PDF JavaScript calls Collab.collectEmailInfo — CVE-2007-5659 is a buffer overflow in Adobe Reader triggered by a long argument or heap-sprayed message field passed to Collab.collectEmailInfo(). Part of a series of Acrobat JS API exploits. (identified after JavaScript deobfuscation)
  • 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.
  • 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.

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0039_000.js
a9bf450b0e3e5554ebd2ee4f245c89034adf403cfb5f567550530ee8e40ee143
pdf-javascript-stream PDF /JS object 39 at offset 0x16F 19566 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
e71bce33d303a704db1ae7ac3ddcdedcf008ba987e73a469e26089921d570909
deobfuscated-js numeric array XOR decoded JavaScript at offset 0x16F 5380 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 9 eval/decoder/string-building token(s).
legacy_pdfkit_stage_001.js
727b0fc42b667c4cb740f65b825b0efdab30bc0d51f47e0485476a97e370454c
deobfuscated-js numPages XOR decoded JavaScript at offset 0x16F 5380 bytes