Malicious PDF — malware analysis report

Static analysis result for SHA-256 d137d0b24d259180…

MALICIOUS

PDF

75.9 KB Created: 2021-07-13 19:06:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: a496287833089aaa8e9c1e0843ced931 SHA-1: bf71a27bf10344eb75418f415c0436a62c4aa8e1 SHA-256: d137d0b24d25918075a8e9b8c533de3cc7c341d453c3ee02950e3e9004fcade9
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF document that contains a lure for a free download, indicated by the 'PDF_SEO_UTM_REDIRECTOR_LINK' heuristic. This lure points to a redirector URL which ultimately leads to a phishing site. The ML classifier and ClamAV detection further support its malicious nature. No scripts were extracted, but the overall pattern suggests a phishing attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.7746

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/gOBB6uaVNRA/square?utm_term=cbse+9th+class+science+book+solutions+pdf+free+download PDF link annotation
    • https://static1.squarespace.com/static/60aac4e0d5abe22cec5c4b22/t/60e8ec9bdc37083541b63df7/1625877659997/kaliv.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf69b23f3791685666e32d/t/60e8a09f6a023653f6c1a9e0/1625858207589/data_structure_tree.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf69b23f3791685666e32d/t/60eca8b03631fd4ab819d8ff/1626122416617/cook_county_small_estate_affidavit.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac59fb7e9621e2f466549/t/60ed7d733b21860fe6720b53/1626176883136/roman_numbers_201_to_300.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_off0000c4cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4CF 16924 bytes
SHA-256: c8c3388cd8850c2245831c44706af44220205bc30ae221de7f6199d1a5ccc958
font_01_sfnt_off0000f0b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0B5 11336 bytes
SHA-256: 38c181c361e31904b0deb93d826841372f60b621345c38567f671dc728a9490f
font_02_sfnt_off00010b32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B32 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1