Malicious PDF — malware analysis report

Static analysis result for SHA-256 85d7c4bfbafe8acd…

MALICIOUS

PDF

75.2 KB Created: 2021-07-13 16:51:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: d885bb9214cbd59ec90a40d9c1069178 SHA-1: d3d21f160f5f36da19cd7a6335db69d53a24506d SHA-256: 85d7c4bfbafe8acd6527c7630f88fd3caba5c3593a322167b81f65f87ef9696b
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a high-severity rule indicating an image lure linking to an SEO redirector for free downloads. The ML classifier and ClamAV also identified it as malicious. The primary IOC is the external URI which appears to be part of a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.7703

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://catamma.ru/square?utm_term=sago+palm+planting+outside PDF link annotation
    • https://static1.squarespace.com/static/60bf6bff0d8d387fecc8b153/t/60ec79df8bb04542cee377a2/1626110431909/romance_anime_with_fighting.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac4e0d5abe22cec5c4b22/t/60ec92457dc7460dd09c0748/1626116677893/73063625885.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6c89a2b0b938881bcf91/t/60ec7ac5e64ce5371633e75e/1626110661816/foreshadowing_in_english_literature.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_off0000c165.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC165 17660 bytes
SHA-256: 2f8e03e8bab1976c155127535a94cc505b96411d2f2c8eb92c8dfb4bdeedf19c
font_01_sfnt_off0000f07c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF07C 10812 bytes
SHA-256: 47577979b474f606038adaa23b59ea6de307539f270fe584cca320af18137e59
font_02_sfnt_off0001092c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1092C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1