Malicious PDF — malware analysis report

Static analysis result for SHA-256 b76c4910d7c637f3…

MALICIOUS

PDF

15.1 KB Created: 2009-06-06 12:30:26 +03:00 Authoring application: NitroPDF 6.0 (via BCL easyPDF 6.00.20)
MD5: 36a7774ba87be15b6b6f81e547209e8d SHA-1: 4a1b97b4e9a47662a5b6a5e5cc924813d24ae8af SHA-256: b76c4910d7c637f32ebf175247d489a311c2a584a1ac6d6af0eeda97abd4c044
430 Risk Score

Malware Insights

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

The PDF contains a highly obfuscated JavaScript stager that utilizes eval() and decodeURIComponent to reconstruct and execute exploit code. This stager targets multiple Adobe Reader vulnerabilities, specifically CVE-2009-0927 (Collab.getIcon), CVE-2007-5659 (Collab.collectEmailInfo), and CVE-2008-2992 (util.printf). The primary intent is to exploit these vulnerabilities to download and execute a secondary payload, as indicated by the 'Pdf.Dropper.Agent-1828906' ClamAV detection and ML classifier score.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 11

  • 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)
  • 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.Dropper.Agent-1828906 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Dropper.Agent-1828906
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • Shuffled variable-fragment JavaScript stager high PDF_SHUFFLED_VAR_JOIN_JS_STAGER
    PDF JavaScript stores an exploit stage as many randomly named string fragments, rebuilds the fragment order through a name array and eval(join('+')), then decodeURIComponent/evals the result. The decoder requires a large variable table and only fires when the recovered stage contains concrete Acrobat exploit JavaScript.
  • 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.
  • PDF paints image(s) but contains no text operators info PDF_IMAGE_ONLY_LURE
    PDF has 1 image XObject(s) and the content stream contains no text-emitting operators (BT/ET, Tj, TJ, ', ") in either raw bytes or decompressed streams — this is the screenshot-as-PDF pattern used to bypass text-based scanners and to deliver instructions purely through rendered pixels. It is informational unless paired with invisible links or risky URI context.
  • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0015_000.js
15c06a4324a6440edaaa846a2b81b8d5116547b435cd8118f183bd0612d13f66
pdf-javascript-stream PDF /JS object 15 at offset 0x315 29157 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
shuffled_var_join_stage_000.js
c1d66e3eff515e496e0868323bafd161019c5f6a1a34c9be0f94b371ee9ed10a
deobfuscated-js shuffled variable-fragment join decoded JavaScript object 15 at offset 0x4BB5 4963 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 7 eval/decoder/string-building token(s).
shuffled_var_join_stage_001.js
1f16b174a3424bc3264a280869b53a2612cce3b966c6d89cc5382007651c8b39
deobfuscated-js shuffled variable-fragment join decoded JavaScript object 15 at offset 0x43BB 5347 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 6 eval/decoder/string-building token(s).
shuffled_var_join_stage_002.js
c2ec1bcda3c37b1989f5e981cc4c9bc409e6564b3de381bff29e6cf5ad7479d5
deobfuscated-js shuffled variable-fragment join decoded JavaScript object 15 at offset 0x43BB 4959 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 7 eval/decoder/string-building token(s).