Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1eaa7680839c581…

MALICIOUS

PDF

180.1 KB
MD5: dccea4e6f63e824d917e402eec260d1a SHA-1: d503ae5703cbefff38f28f52b89edf4a6531bb9e SHA-256: a1eaa7680839c5814966dca6eacf02f6cfce946ca89b33171f9f20cac8cb3345
318 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript 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. This JavaScript is further identified as malicious by ClamAV detections, including 'Js.Exploit.Shellcode-18'. The primary function of the embedded scripts appears to be the exploitation of these PDF vulnerabilities to download and execute a secondary payload, as indicated by the 'EXTRACTED_FILE_CLAMAV' heuristic. The obfuscated nature of the JavaScript and the exploitation of known PDF flaws suggest a downloader or dropper functionality.

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
51c345534887428ce683fbd137facd843b24aa04571189d9d4086646064d29d9
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
6d04bb9490b1624931f79f2224087a0b279dc39fd73b6abb96f95f41033523b5
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0xC9A 20099 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 11 eval/decoder/string-building token(s).