Malicious PDF — malware analysis report

Static analysis result for SHA-256 b507a549546a3d4a…

MALICIOUS

PDF

299.2 KB
MD5: ecf35837d3a8ca2857feee9e72a68ccc SHA-1: e5fea2811ab345fc6de3f463ffdf93fe739e46fe SHA-256: b507a549546a3d4a08ca3a88603fa0ef6bbce908eefe99577920cba7ea1990aa
318 Risk Score

Malware Insights

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

The sample is a PDF file detected as malicious by ClamAV (Pdf.Exploit.Agent-36307). Multiple critical heuristics indicate the exploitation of CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992 through embedded and obfuscated JavaScript. An extracted JavaScript file (legacy_pdfkit_stage_000.js) was also flagged by ClamAV (Js.Exploit.Shellcode-18), suggesting it contains shellcode or further malicious functionality. The embedded JavaScript is designed to be executed by the PDF reader, likely to download and execute a secondary payload.

Heuristics 8

  • 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-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.
  • 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_obj0008_000.js
e5403c36efe7c15d3a80604c39879eb9d788e08462b740a723c826ea9c975d5b
pdf-javascript-stream PDF /JS object 8 at offset 0x1E7 3462 bytes
Detection
ClamAV: Pdf.Exploit.Agent-36307
Obfuscation or payload: unlikely
legacy_pdfkit_stage_000.js
7e44fabaf5ad02959bc70676c75af259e827508a818be71c2d64acfd65b4531a
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0xFA1 20141 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 11 eval/decoder/string-building token(s).