Malicious PDF — malware analysis report

Static analysis result for SHA-256 44c1f6f7c1bed148…

MALICIOUS

PDF

85.5 KB Created: 2021-07-19 15:48:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 08dd4fecdb3906cdfabbc7914e256147 SHA-1: ffe1fa6635bb4b4edf2913de0c95ebb2c8e4e931 SHA-256: 44c1f6f7c1bed1485684a86e6dfe460c0bf1b0df9709600e2cc80460b7be7b77
96 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to compromised WordPress sites and using disposable hosting. The ML classifier also flagged this PDF as malicious with high confidence. This suggests the document is part of a link farm or SEO poisoning campaign, potentially redirecting users to malicious sites or hosting malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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 http://wksystems.net/HotelEstimator/userfiles/file/bufakofutopetesa.pdf In PDF document text
    • https://vinisfarm.com/wp-content/plugins/super-forms/uploads/php/files/7e7ab4455e6406399e7504546a1bc47c/94219788813.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/43d97a8366cb5bb0fdaaa4bd65a39608/48278535205.pdfIn PDF document text
    • https://ssvacancy.com/ckfinder/userfiles/files/3747655318.pdfIn PDF document text
    • http://katachizu.com/img/news/files/dibagip.pdfIn PDF document text
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609ddb4613fd6---fetujeduguwodigo.pdfIn PDF document text
    • http://anthonyvienna.com/sites/default/files/file/rotozujewanad.pdfIn PDF document text
    • http://halvani.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b16d886b74d---67016649302.pdfIn PDF document text
    • https://www.ediliziaindustriale.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c84fe85010---zewonilato.pdfIn PDF document text
    • http://salukool.ee/upload/userfiles/file/65601167415.pdfIn PDF document text
    • http://tinhdaurosa.com/Images_upload/files/nemeb.pdfIn PDF document text
    • https://2greenchicks.com/wp-content/plugins/super-forms/uploads/php/files/204dbae32ce1b3c7522a3771449eadd9/69853499049.pdfIn PDF document text
    • http://soflacops.com/clients/83266/File/82580186596.pdfIn PDF document text
    • http://ar-intl.net/wp-content/plugins/super-forms/uploads/php/files/6tbv11dds9tl5ua5n14t0etrv0/15730245128.pdfIn PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606c978aaad11---vugeravekelo.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/1609100f863534---57799425196.pdfIn PDF document text
    • https://z87992961.com/upload/files/20210708052512.pdfIn PDF document text
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c3278ed2b4---19151659935.pdfIn PDF document text
    • https://carrieres-pierre.com/userfiles/file/pivatiwogepikopi.pdfIn PDF document text
    • http://amphorabeautyclub.com/campannas/file/sewuzulozumawuxu.pdfIn PDF document text
    • http://xedaptap.net/userfiles/file/93218569398.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/475173201f59efbd63ad839405cedd4e/79478633485.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=how+do+you+know+when+god+has+answered+your+prayersPDF 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_off0000ec7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC7B 10816 bytes
SHA-256: 64fcdb2d2f8fb250bba8632088e96e292b8b665ac771883f6ba19be9bd9a6901
font_01_sfnt_off00010533.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10533 16672 bytes
SHA-256: 2805b1f9af8e96fe1777d89159c2e7b30ff4b5095a6221b3a69a4a0ff57c3240
font_02_sfnt_off00013071.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13071 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1