Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc485a06a9d22a07…

MALICIOUS

PDF

80.1 KB Created: 2021-06-26 01:02:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 23cf7d54454172cb5b6b5da8ddf32920 SHA-1: b994a62383a2c8eee777fd7261a7257804b9b897 SHA-256: dc485a06a9d22a0741a80495469e757be94989c1e66125b9d07e45183412dda3
96 Risk Score

Malware Insights

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

The ML classifier strongly indicated maliciousness, and multiple heuristics identified the PDF as a link farm pointing to compromised CMS upload directories. The document body was unreadable, but the presence of numerous external URIs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggest the primary purpose is to redirect users to potentially malicious or SEO-manipulated content. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/9ad5e2925b6438c151292da7f0dd0275/pumudata.pdf In PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/160af5e1ab162e---99745113375.pdfIn PDF document text
    • https://vickers-electronics.co.uk/wp-content/plugins/super-forms/uploads/php/files/85dd40eb7106918387f9f9b3ceb51df6/7074403506.pdfIn PDF document text
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609017e92aa24---wajosakaluzijiwisuki.pdfIn PDF document text
    • http://wecans.net/_UploadFile/Images/file/61254192865.pdfIn PDF document text
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/160a1da82a638b---34901349631.pdfIn PDF document text
    • http://ampletrekking.com/userfiles/file/memugutemixifisoxewa.pdfIn PDF document text
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c47a3257c1c---16752106785.pdfIn PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ca0e2bde36c---fedopudufaju.pdfIn PDF document text
    • https://area34.info/wp-content/plugins/super-forms/uploads/php/files/5v79e0icelns28dl8d0t6peju7/26732925099.pdfIn PDF document text
    • http://purpledoorchurch.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089e920e7015---13779707837.pdfIn PDF document text
    • http://www.peopleoftheheath.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096729216976---87034256195.pdfIn PDF document text
    • https://seataclightingalaska.com/wp-content/plugins/super-forms/uploads/php/files/8562cef2223a9f4fdf0c59d42201b9bb/tifokem.pdfIn PDF document text
    • http://tauben-buchmeier.de/kleinberliner-schuetzen/userfiles/files/43330655801.pdfIn PDF document text
    • https://dmvassociates.com/wp-content/plugins/super-forms/uploads/php/files/4517054db00350bbe2ef4c49c8a31c16/89257575357.pdfIn PDF document text
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160944bfc164cc---50941103766.pdfIn PDF document text
    • https://tigercabinetry.com/wp-content/plugins/super-forms/uploads/php/files/b0c99c6357b252c0c0129f06a07cf884/jegipetigekupubu.pdfIn PDF document text
    • http://www.asap-recruitment.net/upload/file/fakijosavoni.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/c3808d3b076df8cc272c49f2a70945f9/bivegirone.pdfIn PDF document text
    • https://giustofiori.it/file/dewudi.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607e8928acb37---62138286472.pdfIn PDF document text
    • http://www.loicadesacavem.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160a10dde5482f---24274582039.pdfIn PDF document text
    • http://anhuizhkj.com/upload_fck/file/2021-5-20/20210520074111160997.pdfIn PDF document text
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1609d9f160184c---wobun.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=another+word+for+consistentPDF 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_off0000d4f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4F8 10432 bytes
SHA-256: df82463a07c5e7537ebc71b0db1c07f17b42540f87892d26e04ad8faebaf27fc
font_01_sfnt_off0000eca6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECA6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000104b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104B8 17656 bytes
SHA-256: 357c9e5cdf421ec1b4d1a5af359751bb33c55561bef7075eb272ce92b4df3697