Malicious PDF — malware analysis report

Static analysis result for SHA-256 857e078ac47e2a59…

MALICIOUS

PDF

180.1 KB
MD5: e0b16fa544de9543a5b7d496e59d7735 SHA-1: 0e1f0bad2775fe54082e158b6c7958c4837f34ea SHA-256: 857e078ac47e2a59f48ccb765a3ca03c2c98710d02008dac66991741aeb398a6
318 Risk Score

Malware Insights

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

The PDF file contains multiple critical heuristic firings indicating exploitation of CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992 through embedded JavaScript. The extracted JavaScript streams, particularly 'legacy_pdfkit_stage_000.js', are heavily obfuscated but are indicative of a downloader or exploit loader. The presence of ClamAV detections on both the main file and extracted artifacts further supports its malicious nature. The likely intent is to leverage these vulnerabilities to execute arbitrary code, leading to the download and execution of a second-stage 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-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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0008_000.js
604dbb83fb7b227e4ea4eea5350a040a0e64c3351dd150d476c39c4e265d8a2a
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
190964d4cc5ae84f0a6896bf9addbc888950f5df1e7a3877f952c3d467f787a9
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0xC9A 20099 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 11 eval/decoder/string-building token(s).