Malicious PDF — malware analysis report

Static analysis result for SHA-256 961a4b9a4fc777f5…

MALICIOUS

PDF

180.2 KB
MD5: 35d539e043ef8a4b4d1e45f393bc1e0c SHA-1: 66307ea229819de7ec07c9f4c9764184cf737235 SHA-256: 961a4b9a4fc777f51dcf177f4b5916609380d81877d5f25345e3a9b00d52844e
318 Risk Score

Malware Insights

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

The sample is a PDF file that leverages multiple critical vulnerabilities (CVE-2009-0927, CVE-2007-5659, CVE-2008-2992) by executing embedded JavaScript. ClamAV detections on the main file and an extracted JavaScript artifact indicate it's a malicious exploit. The embedded JavaScript is heavily obfuscated, but the presence of exploit-related detections suggests it's designed 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-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
30003cbf8a589157190712fdc06d633757f396345725182f389a3d41a4ac273d
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
cf8fab91ffb9cf819f0c0b3d98e4798e61bf3ed37da5eb5f5ef0d04ee650ffe3
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0xC9A 20111 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 11 eval/decoder/string-building token(s).