Malicious PDF — malware analysis report

Static analysis result for SHA-256 50426ca30049eac2…

MALICIOUS

PDF

5.9 KB Created: 2008-09-24 19:47:56 Authoring application: Adobe (via Notepad)
MD5: 4f0cb89dd1e04b4f01c24c128c2fa3a1 SHA-1: 6bad882e2525e5cb8fc061ac13216f67cf28336e SHA-256: 50426ca30049eac22329964720063badb95346e404b20873216cd9685afa897e
298 Risk Score

Malware Insights

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

The sample is a PDF file that leverages critical vulnerabilities CVE-2009-0927 and CVE-2007-5659. These vulnerabilities allow for the execution of embedded JavaScript, which in turn is detected as a shellcode exploit. The primary intent appears to be the execution of a malicious second-stage payload, as indicated by the ClamAV detections on both the original PDF and the extracted JavaScript artifact. The obfuscated JavaScript and the use of eval() further support this conclusion.

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)
  • ClamAV: Pdf.Exploit.Agent-35931 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-35931
  • 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.
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • 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_obj0006_000.js
a9336ca527f26ef1e3bc90fd286fdb50966b62673cd35d2f88bae7667b10c93c
pdf-javascript-stream PDF /JS object 6 at offset 0x1419 801 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
186340241e5fafa3955e017cac362435f981c98eb57e49c76906eb446522d672
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x16E 5129 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 9 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).