Malicious PDF — malware analysis report

Static analysis result for SHA-256 e845d90845286935…

MALICIOUS

PDF

88.3 KB Created: 2021-09-05 11:41:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 2a4ec6fa64405c4e2fe0c5da638d6f0d SHA-1: 952c6c133657365b61c58450c2c9c1de1d514763 SHA-256: e845d908452869357bd33c5afeac21affa4568cabfc5d056ef9fe8b176ec6f6b
96 Risk Score

Malware Insights

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

The PDF was flagged by an ML classifier as malicious and contains numerous embedded URLs. Several heuristics indicate it functions as a link farm, pointing to compromised CMS uploads and disposable hosting domains. The primary purpose appears to be directing users to external sites, potentially for SEO spam or to host further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://nkcophs50threunion.com/clients/0/01/014062e559e26c1cf0711bcec4e573ae/File/4415622207.pdf In PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/5hihblid1hdag8kc1gcq56f4m5/44402096807.pdfIn PDF document text
    • https://gastrotest.co/ckfinder/userfiles/files/kovofedabukonoki.pdfIn PDF document text
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607eb2e8d4a1d---vufetenunotud.pdfIn PDF document text
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c6283db2eaf---bonefotusiruduvisoz.pdfIn PDF document text
    • http://opakowania-loga.pl/zdjecia/fotki/file/5198854624.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608459876e4e3---vakakevi.pdfIn PDF document text
    • http://beijingteye.com/upload/files/82744626126.pdfIn PDF document text
    • http://showpalmedical.com/userfiles/34361843377.pdfIn PDF document text
    • http://nensi.si/upload/file/11376039144.pdfIn PDF document text
    • http://originalcheck.it/public/img_admin/file///53133907905.pdfIn PDF document text
    • https://giasutainha24h.com/upload/files/96957917166.pdfIn PDF document text
    • http://cioccolatogallucci.it/userfiles/file/rezapazataf.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/16126b06e62980---besuvuwovinidibewuxixa.pdfIn PDF document text
    • http://xindeshiye.com/uploadfile/file///2021080114465066.pdfIn PDF document text
    • https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131f4ab67929---75298507445.pdfIn PDF document text
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/ee57231b16c9713bbaa89165511c0c2e/859607722.pdfIn PDF document text
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160beb5aa17da0---28912363772.pdfIn PDF document text
    • http://lsbwg.com/ckfinder/userfiles/files/20210716/2344327057.pdfIn PDF document text
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/160b84b10beac5---79425418530.pdfIn PDF document text
    • http://purel-biopharm.com/upload/files/durirolulawekitega.pdfIn PDF document text
    • https://xn--80adj7cxa.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/ef6f3f7c457ba425019ef8dc4110dcf6/67634567787.pdfIn PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/lfikgm58m883i57skil8fm2sb4/9634559787.pdfIn PDF document text
    • https://fond.ru/userfiles/file/nexulerijisuranatanive.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087b6b6ea6c2---nunezabilu.pdfIn PDF document text
    • http://mea-travel.pl/userfiles/file/71745186880.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=glosario+de+acordes+para+guitarra+acustica+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_off0000ef12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF12 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010724.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10724 19280 bytes
SHA-256: 378b41a14ecb8e02ed4751df5507e67d98b3d55025d88622aa96a41df02c43b7
font_02_sfnt_off0001386e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1386E 10828 bytes
SHA-256: 3c95a2bae09ab38fbb34688c2a7482e08e64712137e8103531c7ea69c6e0e735