Malicious PDF — malware analysis report

Static analysis result for SHA-256 400cbc7b8117c785…

MALICIOUS

PDF

5.9 KB Created: 2008-09-24 19:47:56 Authoring application: Adobe (via Notepad)
MD5: 074b9706cc33fa374a43999b1673f041 SHA-1: 2a9e8aee1d58ed124c7712f5cb861366ab6c04b5 SHA-256: 400cbc7b8117c785e97d0f591ab24c6161925427f3b7f67bb67c25cc2f670338
358 Risk Score

Malware Insights

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

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 JavaScript streams, particularly 'legacy_pdfkit_stage_000.js' and 'legacy_pdfkit_stage_001.js', are identified as exploit stages and contain obfuscated code. ClamAV detections further confirm the malicious nature of the file and its extracted artifacts. The primary attack vector appears to be leveraging these CVEs to execute arbitrary code, likely to download and run a second-stage 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
6c24203a0fc41cda25c8aaadf316a663000b4ffff4d5ad573f0a4eb78fc8c16b
pdf-javascript-stream PDF /JS object 6 at offset 0x137D 1006 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
6bb56548d4d01fe19298f779d0648d8c3d8bfd69e5a228531f7983a0d637aa1d
deobfuscated-js metadata placeholder percent-decoded JavaScript at offset 0x16E 4953 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
e15939a04c1c52486750ef296b9e9dcf8a3c381b0f82cc7ff80aab1dd1eb39df
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x16E 4949 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).