Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd4965518c1d6d89…

MALICIOUS

PDF

74.1 KB Created: 2021-07-13 22:32:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: beefeee8064af1043c79d855e77750c1 SHA-1: e3b3a4031753952108d9be3193d51056ce11ba27 SHA-256: cd4965518c1d6d896397b95558fd0faff4f6439bb6dc57c274f0ac531ab4a19e
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, with heuristics indicating it uses an image lure linking to an SEO redirector for phishing. The embedded URL points to a Google feedproxy, which is likely part of a redirection chain to a malicious site. No scripts were extracted, but the overall pattern suggests a phishing attempt disguised as a free download.

Machine Learning

  • Nyx PDF Classifier malicious score 0.7218

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • 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 https://feedproxy.google.com/~r/sq/ugae/~3/nCRFBnYrBHY/square?utm_term=polynomials+and+factoring+unit+test PDF link annotation
    • https://static1.squarespace.com/static/60aac59fb7e9621e2f466549/t/60e899d04471185a9cdc3c93/1625856464900/87913782005.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf69b23f3791685666e32d/t/60e8e55d309bd63f3d8302ab/1625875805685/ritifisan.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac59fb7e9621e2f466549/t/60e861ed54aeb3784727b217/1625842157110/56507438731.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6bff0d8d387fecc8b153/t/60e8fb20566ded7d61ab5582/1625881376959/solar_air_conditioning_system.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bee8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBEE8 11032 bytes
SHA-256: 4aa7465d04f5ba5908b972983b9f9b153d9c77086663286b3577c22329e9fb91
font_01_sfnt_off0000d86c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD86C 16888 bytes
SHA-256: 9be2f8510a35c92f37887596c82799d64c561f6f420fb3dc9da4ff4be161420e
font_02_sfnt_off00010485.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10485 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1