Malicious PDF — malware analysis report

Static analysis result for SHA-256 a388834ce7538442…

MALICIOUS

PDF

5.6 KB Created: ert Authoring application: Adobe (via asd)
MD5: c3b8afb13b9fbbbd8a2b29ccc4d3aa78 SHA-1: 5bf2d992ac63c1a0d9c0f6aeaa5a6cb40ae6f7b1 SHA-256: a388834ce7538442eecf57e5471647575ef331510f7ce792d200844308c4d6fb
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-2009-4324, CVE-2009-0927, and CVE-2007-5659. The embedded JavaScript stream was further identified by ClamAV as Js.Exploit.Shellcode-18. The deobfuscated JavaScript, named legacy_pdfkit_stage_000.js, is highly suspicious and likely responsible for downloading and executing a second-stage payload.

Heuristics 7

  • media.newPlayer — CVE-2009-4324 critical CVE exact CVE_2009_4324
    PDF JavaScript calls media.newPlayer — CVE-2009-4324 is a use-after-free in Adobe Reader's multimedia plugin triggered by media.newPlayer(). Actively exploited as a zero-day in December 2009. (identified after JavaScript deobfuscation)
  • 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)
  • 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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
legacy_pdfkit_stage_000.js
2dae3c21ea00a62cbd2f4ac0dfca8a80388138e9dcd9e7bcc52d7dac53421b74
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x1B7 11409 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 12 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).