Malicious PDF — malware analysis report

Static analysis result for SHA-256 cfa28d0bc5863d2a…

MALICIOUS

PDF

74.5 KB Created: 2021-07-14 02:40:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: dc9058f59b92dd09b7551895a1b487dc SHA-1: c70d479cfcb70d9e9692c4e5f97d08e5c975d1f3 SHA-256: cfa28d0bc5863d2a3e3df3c3d6ae8d1f0a8475f13f6b900d430fe4bd91a3914c
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF document flagged by ClamAV as Pdf.Phishing.Trojan. Heuristics indicate it uses an image lure linking to an SEO redirector, a common tactic for phishing or malware distribution. Although the document body is heavily obfuscated and unreadable, the presence of embedded URLs and the ML classifier's high confidence score suggest malicious intent. No scripts were extracted, but the PDF structure itself is indicative of a phishing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9680

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/IdU8rIDf9lQ/square?utm_term=distal+radius+fracture+plate+fixation PDF link annotation
    • https://static1.squarespace.com/static/60aac59fb7e9621e2f466549/t/60eda7ef03cb9e0b597a0292/1626187759460/christmas_worksheets_for_2nd_grade.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6cad3a95e91b59aa2418/t/60e86c80f67b8714f8047450/1625844864420/watch_50_shades_freed_online_for_free.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6bff0d8d387fecc8b153/t/60ede3079779423221e07c2c/1626202887466/50362650801.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac5994c6b1805bc4acbdb/t/60edec7c1c6c1a61d5268dc1/1626205309068/57923691174.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6cad3a95e91b59aa2418/t/60ed8939c50d503b9d5949c6/1626179898015/braille_for_blind.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6bff0d8d387fecc8b153/t/60e81dd023621b4743e68ab9/1625824720274/therapy_in_swahili.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf69b23f3791685666e32d/t/60ec8fbe83836e7a7d61c0dd/1626116030910/logic_puzzles_with_clues.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6bff0d8d387fecc8b153/t/60edef52d6ef6771c1ddb1be/1626206034274/zasipirad.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_off0000c21b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC21B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000da2d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA2D 16172 bytes
SHA-256: 51fd22250a12c83b209c997f4dedadff8eae009c125f9bbade54ac87a4c6b171
font_02_sfnt_off00010410.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10410 10816 bytes
SHA-256: 15fb267248cfd184588b4a2e7592a74f20e903a4246f7f6e658a28de3d03ea25

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