Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac97b4ab9ccaf911…

MALICIOUS

PDF

79.6 KB Created: 2021-09-03 08:01:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 13216a4f0d585042fbe5517830ff2f66 SHA-1: b4420c153ebbbd9b56cbcceb64a78a3335134ca6 SHA-256: ac97b4ab9ccaf9110c7d678955867f44f537d6736319c2d81ff62942a3875058
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains numerous links, many pointing to compromised CMS uploads or disposable hosting, indicating it functions as a link farm. The primary purpose appears to be directing users to external, potentially malicious websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9945

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://ebslang.net/_UploadFile/Images/file/67800137422.pdf In PDF document text
    • http://glina-master.ru/admin/ckfinder/userfiles/files/nuperan.pdfIn PDF document text
    • https://drbumbnursinghome.in/ckfinder/userfiles/files/64744692848.pdfIn PDF document text
    • http://www.k-24.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a8f40c788f---13003275182.pdfIn PDF document text
    • http://kramor.bg/userfiles/file/42929266008.pdfIn PDF document text
    • https://polskieplytki.com/wp-content/plugins/super-forms/uploads/php/files/85f0c7b58fedb6c0bb15850b29941c27/64798554405.pdfIn PDF document text
    • http://annassteen.com/ckfinder/userfiles/files/72060815857.pdfIn PDF document text
    • http://4seasonstours.in/userfiles/file/12945812228.pdfIn PDF document text
    • https://flycam.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16080919ee90a5---doponijodimubuk.pdfIn PDF document text
    • https://rockdental.co.uk/wp-content/plugins/super-forms/uploads/php/files/fbb38b33eded6426466befc06c18f51c/93904822518.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160837ee5b5a5b---gulevatojigisire.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160c42298ceccd---64547100905.pdfIn PDF document text
    • http://www.moteco.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16073015391d4b---21835724443.pdfIn PDF document text
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/0s53oga47p16ha3p9reubu2ueb/50121633475.pdfIn PDF document text
    • https://thechoose.it/file/3557162594.pdfIn PDF document text
    • http://heatexchangersolution.com/upload_fck/file/2021-7-31/20210731095636176107.pdfIn PDF document text
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16123402c98b8f---86729933965.pdfIn PDF document text
    • https://advancedbusiness.co/wp-content/plugins/super-forms/uploads/php/files/54255713b59dc173eedc5f90ec4becba/27564916305.pdfIn PDF document text
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160802ab8559d6---xatuj.pdfIn PDF document text
    • http://abwingsde.com/uploads/files/1315905905.pdfIn PDF document text
    • http://appletechsolutions.com/userfiles/file/kilusatopusifavonoworab.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160855f1fd951f---94065132975.pdfIn PDF document text
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d97c18c340---8619034906.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160c4fdc1ca10b---lonipesanulokupure.pdfIn PDF document text
    • http://nirmalapublicschoolerumely.com/userfiles/file/topagisagegigazadaluzapad.pdfIn PDF document text
    • http://emusicmarket.com/upfile/board/files/87877795078.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=em%C3%ADlio+ou+da+educa%C3%A7%C3%A3o+jean+jacques+rousseau+pdfPDF 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_off0000ca65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA65 19696 bytes
SHA-256: 53194410eb08a5c68329a67d1ee7a7f0502b7cb1a7e0c487584fb2eb77fbc46d
font_01_sfnt_off0000fb81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB81 11568 bytes
SHA-256: b1bf0aca89fe83ac652fb18be1669dd26584da98d084690ee5310c8d24869915
font_02_sfnt_off000115cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115CC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1