Malicious PDF — malware analysis report

Static analysis result for SHA-256 70994a344c99e436…

MALICIOUS

PDF

89.7 KB Created: 2021-09-18 13:15:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: b2ed1b58b40a87f6805d0d6a9620703e SHA-1: bc0a31d417e67bca975637c7c06e3c02ab20d32a SHA-256: 70994a344c99e43657c7e5ebbe3bcaa038d081cdcc675324d1a91d46c4dc7298
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or other PDF files. Heuristics indicate it's a link farm on disposable hosting and uses compromised CMS upload storage. The ML classifier strongly flagged this PDF as malicious, suggesting it's part of a larger malicious infrastructure, likely for phishing or SEO poisoning.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://ketchas.ru/uplcv?utm_term=class+8+maths+textbook+pdf PDF link annotation
    • https://sharenkon.com/files/nasinimefawabaximetizi.pdfIn PDF document text
    • http://garantc.ru/userfiles/file/sisesujemokewexam.pdfIn PDF document text
    • https://marksiegeldds.com/wp-content/plugins/super-forms/uploads/php/files/e6c5d6e2753cfbe46dc125696feac8ee/nuromenuxin.pdfIn PDF document text
    • http://www.xn----9sbkvfu2aex3d.xn--p1ai/ckfinder/userfiles/files/39758480993.pdfIn PDF document text
    • https://beamstraffic.com/amb/userfiles/file/74822275570.pdfIn PDF document text
    • http://bajajsports.com/userfiles/file/81075265316.pdfIn PDF document text
    • http://www.catedralirodahaz.hu/data/editorfile/liredusikunuwozarovux.pdfIn PDF document text
    • http://catwalkexotique.com/userfiles/panuroragipizivuxom.pdfIn PDF document text
    • http://paletydozahrady.cz/ckfinder/userfiles/files/9596021748.pdfIn PDF document text
    • http://stellarvvv.ru/ckfinder/userfiles/files/wikonijonixul.pdfIn PDF document text
    • http://ttworld.hu/uploads/content_files/files/89322654142.pdfIn PDF document text
    • https://giverny-bkk.com/upload/files/62947849060.pdfIn PDF document text
    • https://winpoasia.com/ckfinder/userfiles/files/ragibujemolakiz.pdfIn PDF document text
    • https://cometgroupinternational.com/ckeditor/ckfinder/userfiles/files/7946280190.pdfIn PDF document text
    • http://innobiztour.com/FileData/ckfinder/files/20210901_B9FD787677DDDA2B.pdfIn PDF document text
    • https://www.getfitcrew.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138680ca1feb---76957466208.pdfIn PDF document text
    • https://trexanh.net/upload/files/zegedolefoti.pdfIn PDF document text
    • https://clubforeducation.com/FCKeditor/userfiles/file/82785395861.pdfIn PDF document text
    • http://dataprint.ie/uploads/file/zijosunalozek.pdfIn PDF document text
    • http://exito-opakowania.pl/userfiles/file/29944061168.pdfIn PDF document text
    • https://xn----7sbabak5acz7byau.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/77fe90ebd6cc697a0946aed0b1350f8a/rifov.pdfIn PDF document text
    • http://infosierra.es/images/editor/34817033161.pdfIn PDF document text
    • 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_off0000f8f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8F3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001110a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1110A 11040 bytes
SHA-256: 510c054217373490010a39150d526a4c102f42e9ce6fe4a7461b17992274a211
font_02_sfnt_off00012a97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A97 17940 bytes
SHA-256: aa4cefa1ab58d13e1d8741460783a30b1e397d8a87aef32d3c365b6d554eece2