C6 Messenger Downloader — PDF malware analysis

Static analysis result for SHA-256 730a22584d47c926…

MALICIOUS

PDF

629.8 KB Created: 2011-05-17 09:15:08 Authoring application: Joomla! 1.5 - Open Source Content Management (via TCPDF 3.0.015 (http://www.tcpdf.org))
MD5: a45293d6cfc23391981c629f79e799f1 SHA-1: 982c365f5e8bfbdc94c7bb89185ce7b57eb184e7 SHA-256: 730a22584d47c9265488b1f6a105476451a03b05b04964d5b434cf8155e4f770
100 Risk Score

Malware Insights

C6 Messenger Downloader · confidence 95%

MITRE ATT&CK
T1203 Exploitation for Client Execution

The sample is a PDF file that contains an embedded exploit for CVE-2008-2551, targeting the C6 Messenger DownloaderActiveX. This exploit is designed to download and execute a secondary payload from the URL http://artisanballoonz.com/system/system.exe. The presence of the exploit and the download URL strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9653

Heuristics 3

  • C6 Messenger DownloaderActiveX exploit critical CVE exact CVE_2008_2551
    PDF stream bytes contain HTML/ActiveX content configuring the vulnerable C6 Messenger DownloaderActiveX control with propDownloadUrl and propPostDownloadAction=run. This is the published exploit shape for CVE-2008-2551.
  • Optional Content Group with action trigger low PDF_OPTIONAL_CONTENT
    Optional Content Group (layer) co-occurs with an action trigger — content can be selectively hidden from viewers or scanners while the action still fires on open
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://artisanballoonz.com/system/system.exe
    • http://c6.community.alice.it/download/DownloaderActiveX.cab#Version=1,0,0,1

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_002_off000006af.bin
80ce46be3b4d5733393d911e720cc341eac961413bc8841086c1643fee9fc14b
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x6AF 73272 bytes