Malicious PDF — malware analysis report

Static analysis result for SHA-256 28a6d2ccbe5e6604…

MALICIOUS

PDF

179.9 KB
MD5: 3fbf6c99cb7102327889e1f5c78d25c8 SHA-1: 61afd22a8524350ae62a7c3bc3ed65ddadf1f919 SHA-256: 28a6d2ccbe5e6604079e797cedc0f1a9fedcf0bfdc69f6c59351f418f7a1fe16
378 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File: User Execution T1059.001 Command and Scripting Interpreter: PowerShell T1059.007 Command and Scripting Interpreter: JavaScript

This PDF file is malicious, as indicated by multiple critical heuristic firings related to known PDF exploits (CVE-2009-4324, CVE-2009-0927, CVE-2007-5659, CVE-2008-2992). The embedded JavaScript streams, identified by ClamAV as Js.Exploit.Shellcode-18 and Pdf.Exploit.Agent-36307, are designed to exploit these vulnerabilities. The primary function of the embedded scripts is to download and execute a secondary payload, as suggested by the ClamAV detection names and the nature of the exploits.

Heuristics 9

  • 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-36114 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-36114
  • 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
6c279dbc555103e47695a1830fcf7c5ed219ecdf4b64f52b2af8964bf947e1f4
pdf-javascript-stream PDF /JS object 8 at offset 0x1E7 2687 bytes
Detection
ClamAV: Pdf.Exploit.Agent-36307
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
legacy_pdfkit_stage_000.js
2c092b8faf213a58e8439b83e4f48dd3ec8e3ae3e8c1e0dd369727bca6f124b9
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0xC9A 20075 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