Malicious PDF — malware analysis report

Static analysis result for SHA-256 21cab9e2c06c7d3a…

MALICIOUS

PDF

127.3 KB Created: 2010-04-23 12:43:52 +08:00
MD5: adb56696673659537288ea162514feae SHA-1: 636b34f95d5c1649ddb80ad34e187e041d47b8b8 SHA-256: 21cab9e2c06c7d3ad4643982f11a151f889730c631610e03220a693bb75b5893
204 Risk Score

Malware Insights

MITRE ATT&CK
T1553.005 Mark-of-the-Web Bypass T1105 Ingress Tool Transfer

The PDF file contains a critical heuristic firing for an embedded Windows executable payload. ClamAV also detected this payload as Win.Virus.Expiro-10021101-0. The presence of JavaScript actions and embedded streams further supports the likelihood of this PDF acting as a dropper for malicious executables.

Heuristics 7

  • Embedded Windows executable payload in PDF stream critical PDF_EMBEDDED_PE_PAYLOAD
    PDF stream bytes contain an embedded Windows executable with a verified PE header. Exploit chains often hide droppers inside ordinary streams rather than standard /EmbeddedFile attachments.
  • ClamAV: Win.Virus.Expiro-10021101-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Virus.Expiro-10021101-0
  • 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. (matched inside decoded stream)
  • 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. (matched inside decoded stream)
  • Embedded file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload (matched inside decoded stream)
  • 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://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://ns.adobe.com/xap/1.0/
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/pdf/1.3/

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_010_off00001b62.bin
d666105e42ba6a7a582f943ace136a9583b9d6bf58ceb399b67d93d35f277046		 decompressed-pdf-stream PDF FlateDecoded stream at offset 0x1B62 241664 bytes
Detection
ClamAV: Win.Virus.Expiro-10021101-0
Obfuscation or payload: unlikely
objstm_0040_00.bin
fefb14e8fee47a9a47ffd73a073668c8ba18a685c584141bd8d8f1e2495aa5a1		 pdf-objstm-decoded PDF /ObjStm 40 0 obj (inflated) 1928 bytes
objstm_0062_00.bin
db042848f42b0a9acd44358f906fa7de3c533146faa076d0a822142247116f90		 pdf-objstm-decoded PDF /ObjStm 62 0 obj (inflated) 65 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.