Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b161cea1e64c458…

MALICIOUS

PDF

78.8 KB Created: 2021-04-29 21:05:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: 47350a0c1c9feb0d77639b3c40dff9cd SHA-1: 1eb09fbb53114dbc436649c35378b9316c61d15d SHA-256: 3b161cea1e64c4584b237dfe8e67aea144d0049e84564ab2ef18b3c8d04a9930
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links to external resources, many of which point to compromised WordPress sites hosting other PDF files. This behavior is characteristic of a link farm designed to distribute malicious content or lead users to phishing sites. The ML classifier strongly indicated maliciousness, supporting the assessment of a malicious link distribution pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/47e163522f6d4700bf38c351ce667d18/vojapex.pdf In PDF document text
    • https://aduanaldelvalle.com/userfiles/file/zezagufuxawix.pdfIn PDF document text
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076b00d77b95---83055191826.pdfIn PDF document text
    • http://shmountaineering.co.uk/wp-content/plugins/super-forms/uploads/php/files/8i97mhpvcdar71imnjqv49io35/lipokanipumokiwemurexi.pdfIn PDF document text
    • https://wecafephuket.com/wp-content/plugins/super-forms/uploads/php/files/d3ag1kvqt6i3ra0t9h523njt8i/55040570983.pdfIn PDF document text
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086806e14ff3---85138203306.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/doa3v3koga1fs3hpli5u06bms1/xaliwiritexisoromitepenot.pdfIn PDF document text
    • https://lasvegasrebath.com/wp-content/plugins/super-forms/uploads/php/files/21078fb47c27abf2cd07cdad6ac7cb03/69819976354.pdfIn PDF document text
    • https://pankalconstructora.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c51a3db81b---gonukebafij.pdfIn PDF document text
    • https://mattweidnerlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a6a69aa89c---zobolitaxux.pdfIn PDF document text
    • https://www.adilaltinsoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073c43aa246d---55326159140.pdfIn PDF document text
    • https://jollytime.ru/wp-content/plugins/super-forms/uploads/php/files/8af8a33352065d933481a670de9ccb72/98853611755.pdfIn PDF document text
    • http://www.tenniscanberra.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607d98506ac9f---2248116367.pdfIn PDF document text
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607e2dc2a690d---42669121065.pdfIn PDF document text
    • http://getawaynewzealand.co.nz/wp-content/plugins/formcraft/file-upload/server/content/files/16086a58f11942---tegibugodite.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=japura+river+philip+glass+sheet+musicPDF link annotation
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e8e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8E0 5060 bytes
SHA-256: 7139d5779d01d37a5e7d5d6d53ef6117a596c3e16ba0df19721165ca2f479e7a
font_01_sfnt_off0000fa23.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA23 11024 bytes
SHA-256: 6d664be70290b9b5682a5b1aa8c3b60c549f158e02653e47e13cb65e593427dc
font_02_sfnt_off00011fef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FEF 4324 bytes
SHA-256: 05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176