Malicious PDF — malware analysis report

Static analysis result for SHA-256 11cee21122119f4f…

MALICIOUS

PDF

298.6 KB
MD5: a4f7d3ee2da1a976cd1ad8a456fec9c0 SHA-1: 48e58d8939ae2854f23807611de94d231f62bae4 SHA-256: 11cee21122119f4fa40df3ecefd285c8c49f0a2b3aa7cabe685dc844b915e2f2
570 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.007 JavaScript

The sample is a PDF file that leverages multiple known Adobe Reader vulnerabilities through embedded JavaScript. The JavaScript code is designed to download and execute a secondary payload from provided URLs. The ClamAV detection and ML classifier strongly indicate malicious intent, specifically an exploit kit targeting PDF readers.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 13

  • 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)
  • util.printf — CVE-2008-2992 critical CVE exact CVE_2008_2992
    PDF JavaScript calls util.printf() — CVE-2008-2992 is a stack buffer overflow in Adobe Reader triggered by a long format-specifier argument. Widely exploited in the wild after disclosure. (identified after JavaScript deobfuscation)
  • Pidief-style multi-CVE JavaScript dispatcher critical CVE likely PDF_PIDIEF_MULTI_CVE_DISPATCH
    A single JavaScript body branches on app.viewerVersion and invokes two or more of the canonical Reader sinks (Collab.collectEmailInfo, Collab.getIcon, util.printf with a field-width format string). This is the 2009-2010 Pidief.J multi-exploit landing template: a per-version dispatcher that fires the matching CVE chain for whichever Reader version opens the file.
  • Multi-CVE Adobe Reader JavaScript exploit kit critical PDF_ADOBE_READER_MULTI_CVE_JS_KIT
    One recovered JavaScript stage contains multiple version-gated Adobe Reader exploit branches. This is stronger evidence than independent API keywords: the PDF is selecting old Reader vulnerabilities by viewer version and running heap-sprayed Acrobat JavaScript exploit paths.
  • ClamAV: Pdf.Exploit.Agent-36307 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36307
  • 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.
  • PDF JavaScript shellcode contains an embedded download URL high PDF_JS_SHELLCODE_DOWNLOAD_URL
    Decoded PDF JavaScript shellcode contains a hardcoded http(s) URL stored as little-endian %uXXXX Unicode escapes. Reader exploit shellcode embeds the second-stage fetch URL this way and pulls it down with a urlmon/URLDownloadToFile-style download-and-execute (commodity downloader behaviour rather than a specific Acrobat CVE).
  • 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.
  • 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://abrie.in/x/l.php?s=printf_xa1&
    • http://abrie.in/x/l.php?s=email_xa1&
    • http://abrie.in/x/l.php?s=gicon_xa1&
    • http://abrie.in/x/l.php?s=newp_&

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0008_000.js
4a850dfb1398e50ed6a7246b7bcd2a278c755dafa0f619f76474b43f1c9eff4d
pdf-javascript-stream PDF /JS object 8 at offset 0x1E7 3462 bytes
Detection
ClamAV: Pdf.Exploit.Agent-36307
Obfuscation or payload: unlikely
javascript_obj0008_001.js
c9e5b8e590a9cb6c1823a1d45b82f468f5e5956978409eae69c94d7cf040a02d
pdf-javascript-stream PDF /JS object 8 at offset 0x209 305256 bytes
Detection
ClamAV: Pdf.Exploit.Agent-36307
Obfuscation or payload: unlikely
legacy_pdfkit_stage_000.js
784c54fdd8b5c1e118f39b5a57a54c20cabf06bf92af29457433037e2b925118
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0xFA1 20099 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 11 eval/decoder/string-building token(s).
legacy_pdfkit_stage_001.js
42025b552c7960b53abcd8cd732b01c8d109eccfdfefc352b9826c4d5807d414
deobfuscated-js cross-stage annotation API aliases at offset 0x1E7 81 bytes