Malicious PDF — malware analysis report

Static analysis result for SHA-256 b6fb3e85dfc4ea41…

MALICIOUS

PDF

135.1 KB
MD5: 0103dc9ddfa730af481192b6992b39e3 SHA-1: 3dfc683439ae8ec4049542cd31c1af00f6623a65 SHA-256: b6fb3e85dfc4ea410e21e1b2ec641a75d11b678eacaf14ebcc8e6b1c4c98ebf9
258 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File T1059.001 JavaScript T1059.007 JavaScript

The PDF file contains multiple critical heuristic firings indicating exploitation of CVE-2009-0927, CVE-2007-5659, and CVE-2008-2992. These vulnerabilities are leveraged through embedded JavaScript, which is further confirmed by the extraction of a deobfuscated JavaScript file. The ClamAV detection 'Js.Exploit.Shellcode-18' on an extracted artifact suggests the script's intent is to download and execute a second-stage payload. The obfuscated JavaScript and the nature of the exploits point towards a malicious downloader.

Heuristics 7

  • 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 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
891fa5cc694f8cd0f79f0f2b6b0803158ce77c05f574b0224891cfb94edfc7d3
pdf-javascript-stream PDF /JS object 8 at offset 0x1E7 2105 bytes
legacy_pdfkit_stage_000.js
ec1ae9941da3ed7276544a499e9151201c3dd94a12eb9234264f7360a46e9d35
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0xA54 9024 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 9 eval/decoder/string-building token(s).