Malicious PDF — malware analysis report

Static analysis result for SHA-256 508b9a4a56bbd03a…

MALICIOUS

PDF

7.5 KB Authoring application: Viraciregavi
MD5: 89a7040be185046ebeca945ccd96b063 SHA-1: 2a800e84d109cdc89111ad531c36c4aaf4a35e7e SHA-256: 508b9a4a56bbd03aade14cbf93c293362e927f77cae8479b49c923a4991ca957
378 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that utilizes eval() and unescape() functions, indicating obfuscation. Critical heuristics identify multiple CVEs related to PDF JavaScript exploits (CVE-2009-0927, CVE-2007-5659, CVE-2008-2992), suggesting the primary function is to leverage these vulnerabilities. The embedded JavaScript streams, particularly 'legacy_pdfkit_stage_000.js', are likely responsible for executing the exploit chain. The document body text appears to be nonsensical filler, further supporting a malicious intent behind the document's structure.

Heuristics 10

  • 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-35649 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-35649
  • OpenAction trigger high PDF_OPENACTION
    PDF has an /OpenAction — code runs automatically when opened
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (matched inside decoded stream)
  • 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_obj0007_000.js
8f27493ed150893fee7bbb4c718e9aa55054e6b909d45baef6051abecf472732
pdf-javascript-stream PDF /JS object 7 at offset 0x45A 5796 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 11 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
1e0c8ca4c6180400afd62497a161d41969b04e1091a2d4ffa9764c7f00cf51a1
deobfuscated-js string-concatenation normalized Acrobat API aliases at offset 0x45A 851 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 long base64-like blob(s).