Malicious PDF — malware analysis report

Static analysis result for SHA-256 ae3981b988647bf6…

MALICIOUS

PDF

73.4 KB Created: 2021-07-12 20:48:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: a56e9ce9ca25965138c1ed996892353d SHA-1: 9ca5d6b38513f43f8f3e7e9442695a80194bfb21 SHA-256: ae3981b988647bf6d00e90dafad1953f4fb6556fa581506fdd375588487f5355
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains heuristics indicating it is a phishing lure, specifically using an image to redirect the user to an external URL. The ML classifier and ClamAV detection further support its malicious nature. Although no scripts were explicitly extracted, the PDF structure and redirection capabilities suggest an attempt to lead the user to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6882

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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/gOBB6uaVNRA/square?utm_term=foreshadowing+in+night PDF link annotation
    • https://static1.squarespace.com/static/60aac4dd19f082755c4e5c69/t/60e87eaf56d6f74a83388ba7/1625849519500/focal_atypical_endometrial_hyperplasia.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac4dd19f082755c4e5c69/t/60ec7c9c19a16f038d619b88/1626111132948/kilebexadoroxowogi.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac59fb7e9621e2f466549/t/60e8d05fb166174ac2d6b1d6/1625870431192/flat_tops_trail_scenic_byway.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_off0000c482.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC482 14956 bytes
SHA-256: a9fcaf5d5f41d1c7ead83362f87d17dfd95133eacdb5fff0a7e6416db92da38a
font_01_sfnt_off0000ea20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA20 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010237.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10237 10544 bytes
SHA-256: cf5ca1aaf82dd6df29ba58242c273b917f24bf19f589e6c0443063329f34f178