Malicious PDF — malware analysis report

Static analysis result for SHA-256 e78b7a38fa41d456…

MALICIOUS

PDF

5.9 KB Created: 2008-09-24 19:47:56 Authoring application: Adobe (via Notepad)
MD5: 8617f2bd4d48b0db7e2719d8959b950b SHA-1: f453d71d7dac760256957d00d2b52521f9a6b398 SHA-256: e78b7a38fa41d456cf0b03636f6610b7841e4fae8fefa2c8734eb55ad0057841
358 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript T1204.001 Malicious Link/Object

The PDF file contains multiple critical heuristic firings indicating exploitation of known Adobe Reader vulnerabilities (CVE-2009-0927, CVE-2007-5659, CVE-2008-2992) via embedded JavaScript. The embedded JavaScript streams, particularly 'legacy_pdfkit_stage_000.js' and 'legacy_pdfkit_stage_001.js', are deobfuscated and likely contain shellcode, as indicated by the ClamAV detection on extracted artifacts. The primary function appears to be exploiting these CVEs to execute arbitrary code, likely for downloading and running a subsequent payload.

Heuristics 9

  • 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-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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0006_000.js
82f4334b513a3dacff3eeb496ebc9546f39044ae1ea9a95109121c1f93e5112c
pdf-javascript-stream PDF /JS object 6 at offset 0x1384 906 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
b26ac71afffc0a79d0633bf83aa0ad2f98853faa720bb535b7c0850f9fda2d5f
deobfuscated-js metadata placeholder percent-decoded JavaScript at offset 0x16E 4971 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).
legacy_pdfkit_stage_001.js
2f5086550159dc9164e10f4875bc545cf8532b7a6ac7820c30b2f02b60e09553
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x16E 4967 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).