Malicious PDF — malware analysis report

Static analysis result for SHA-256 c71d5b3d0292c87e…

MALICIOUS

PDF

135.0 KB
MD5: 2b357bb8bea2229fdd77fcda994b6b96 SHA-1: 59bad5b7a3707a8ba5cd7be1e6e8cbd4a218cc6a SHA-256: c71d5b3d0292c87e34dd17bed378ea654e118acd010582ae2947d338e6c7e9bd
258 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that exploits multiple known vulnerabilities including CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992. The heuristics indicate that the JavaScript is obfuscated and likely used to download and execute a secondary payload, as suggested by the ClamAV detection 'Js.Exploit.Shellcode-18' on an extracted artifact. The deobfuscated JavaScript and the PDF launcher's method of concatenating info fields and evaluating the result further support this attack pattern.

Heuristics 7

  • 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 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
f3b1d166dd1958e00d38eed91b855f80733a9522c9e483bf3c5cd859a99f8eb3
pdf-javascript-stream PDF /JS object 8 at offset 0x1E7 2089 bytes
legacy_pdfkit_stage_000.js
ec1ae9941da3ed7276544a499e9151201c3dd94a12eb9234264f7360a46e9d35
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0xA44 9024 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 9 eval/decoder/string-building token(s).