Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8a3115581d96d9f…

MALICIOUS

PDF

91.1 KB Created: 2021-07-18 07:01:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 28ca66773661697630e26bce0009bbc3 SHA-1: 77a3c6e602d4e74cfd7b073ade60e2383f34d572 SHA-256: f8a3115581d96d9fe3c70e130d8ad8168778a689c3f704a8ed979ddcbab0d28e
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as a phishing trojan and ML classifiers indicated maliciousness. A heuristic identified an image lure linking to an SEO redirector, suggesting a phishing attempt. No scripts were extracted, but the presence of external URIs and the overall detection suggest the file is designed to lead users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6187

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/pL_UGxDroB4/square?utm_term=name+the+positions+on+a+ice+hockey+team PDF link annotation
    • https://static1.squarespace.com/static/60aac5994c6b1805bc4acbdb/t/60ec81b554a52c186ce4c7ca/1626112437462/the_lateral_surface_area_of_cylinder_is.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6bff0d8d387fecc8b153/t/60f3783b25edf123065c91c1/1626568763348/bakafenudavanudegewuro.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac4dd19f082755c4e5c69/t/60f0e6814bb49071de15f7e8/1626400386087/trivial_pursuit_trivia_questions_and_answers.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_off000104c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104C7 10676 bytes
SHA-256: 3c41ae753712ca483a3910280da7605e6bcb836fad929afe7d830f57dd1a621f
font_01_sfnt_off00011d26.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D26 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013538.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13538 16636 bytes
SHA-256: 3f0fcb0cc43199463fb61d689039b3949b69ab487f47d96b0a05eae26c0aa44e