Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c5757aa3369e43a…

MALICIOUS

PDF

132.6 KB
MD5: 92a7d500f961696e7932d05e4e8c5b04 SHA-1: 24ebc384c9c1b2518f23de0eb5ed766f52dc12e6 SHA-256: 4c5757aa3369e43a9381ed1deb9505e2fbb57f799d83e433c34e363fa54fff8b
418 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript T1204.002 Malicious File T1190 Exploit Public-Facing Application

The PDF file contains embedded JavaScript that utilizes character-table indexing to evade detection and execute exploits for CVE-2009-4324, CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992. This JavaScript is designed to deobfuscate and execute a secondary payload, as indicated by the 'eval stager' heuristic and ClamAV detections on both the PDF and the deobfuscated JavaScript artifact. The primary goal appears to be the execution of further malicious code.

Heuristics 10

  • 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)
  • ClamAV: Pdf.Exploit.Agent-36388 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36388
  • 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.
  • Character-table JavaScript eval stager high PDF_JS_CHAR_TABLE_EVAL_STAGER
    PDF JavaScript reconstructs an exploit stage by indexing into a small character table, appending hundreds of one-character fragments, joining the array, and evaluating the result. This static fallback fires only after the bounded decoder recovers an exploit-like stage, so it catches this obfuscation even when no single CVE API signature is available.
  • 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0076_000.js
4dd58bf632961944320235a78cfdb62d7ff8d89bc4103954012cb05e93e0e0eb
pdf-javascript-stream PDF /JS object 76 at offset 0x2C2 119375 bytes
Detection
ClamAV: Js.Exploit.HTML-27
Obfuscation or payload: unlikely
char_table_stage_000.js
bcd3315b4ccffe50927142799fdaffb48d8a4af0901f607e5f406b85a8aca7c7
deobfuscated-js char-table indexed JavaScript (PDF /JS object 76) at offset 0x2DC 3864 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 11 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).