Malicious PDF — malware analysis report

Static analysis result for SHA-256 3451e81415a73676…

MALICIOUS

PDF

76.1 KB Created: 2021-09-15 01:25:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 85f4ea8b2b6abf61b4d68b373d3ee4ad SHA-1: 555ea679732fc772c85f2f8cb1b285c3b096a082 SHA-256: 3451e81415a73676e1f7dab248b94cfc8c0a8345b75fba95096f5417919bd123
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The ML classifier strongly indicates maliciousness, supported by heuristics identifying the PDF as a link farm pointing to compromised WordPress sites. These links likely serve as a lure to download further malicious content, potentially exploiting embedded JavaScript. The document's purpose appears to be facilitating the distribution of malware through these compromised hosts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/25cd062441ac529bcfb4ee1cba0c1d2c/82282994354.pdf In PDF document text
    • http://chernogolovka.inhome360.ru/admin/ckfinder/userfiles/files/xajekoga.pdfIn PDF document text
    • https://hotelritariccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/161405df160477---woranonefulotofogefof.pdfIn PDF document text
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1612f7a94dcc7e---15022461957.pdfIn PDF document text
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/eb4a230220d8af8480911dd3a00fb0bc/fokam.pdfIn PDF document text
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/1614118aa6d16b---nawugibepokevudixof.pdfIn PDF document text
    • http://eva.am/files/dd09ba632037f836.pdfIn PDF document text
    • https://mygamedaysports.com/wp-content/plugins/super-forms/uploads/php/files/7a48293b866e0ad6650642df36005bc6/zutevexewaxupe.pdfIn PDF document text
    • http://moskvaznaet.ru/upload/files/68426604895.pdfIn PDF document text
    • https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/161410f5787af5---zefawinozuja.pdfIn PDF document text
    • http://huseyindurmuslar.com/images_upload/files/5186120657.pdfIn PDF document text
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/161411445a3129---tedaruj.pdfIn PDF document text
    • https://dhins.com/testingsites/advantage_aviation/assets/media/file/77921569165.pdfIn PDF document text
    • http://xn--80aer5aza.xn--19-kmcm3c.xn--p1ai/ckfinder/userfiles/files/wewikolaga.pdfIn PDF document text
    • http://odontotecnicacoop.it/userfiles/file/pifupajegidiporufuno.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/kblh8amad0hu3qvi323jb88og6/tirubopebugekoxake.pdfIn PDF document text
    • http://baby-daycare.com/uploads/files/202109040604215902.pdfIn PDF document text
    • http://alt-1c.ru/userfiles/file/samilivafotukodasebukopu.pdfIn PDF document text
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/b421034f3cf99a9b0b10af804c9d48f9/11636160004.pdfIn PDF document text
    • http://yeongwonenc.com/userfiles/file/sakakozizamiv.pdfIn PDF document text
    • http://annabarons.com/files/files/lizidoxizik.pdfIn PDF document text
    • https://xistenze.nagydavid.com/files/files/mibabopaz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=unity+android+live+wallpaperPDF 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://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_off0000c6c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6C1 16848 bytes
SHA-256: 6d55d9da9ee2d5c4dafcf90b41b84dc0fde09447f08473a7ba4bba65101433d4
font_01_sfnt_off0000f28e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF28E 10492 bytes
SHA-256: 7fb27787217bc5c5e780b4181b08a027dbfdbb98a870d844da71630a2ab9d67f
font_02_sfnt_off00010a8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A8B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1