Malicious PDF — malware analysis report

Static analysis result for SHA-256 956caecc3e2e56c9…

MALICIOUS

PDF

73.6 KB Created: 2021-08-09 22:17:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: d5e78cfa52f0cca3ed3f75f3717e2554 SHA-1: df3efdd164e6ba3f693112b1fc340db5095154be SHA-256: 956caecc3e2e56c99f32853d1a9e79f5e71a5caf0f8a83fc8823cea6f1df12fc
96 Risk Score

Malware Insights

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

The ML classifier and heuristics indicate this PDF is malicious, likely functioning as a link farm. It contains numerous embedded URLs pointing to various domains, including those hosted on compromised WordPress sites and potentially disposable hosting, suggesting an attempt to redirect users to malicious content. The presence of multiple PDF link farm heuristics reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://digireg.cn/upload/tuwijedebupulupiromovibe.pdf In PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070b0952ff6b---ratotidegetagisafav.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070e27d94c38---rusofafaman.pdfIn PDF document text
    • http://szao-spb.ru/images/news/file/raperuwudekug.pdfIn PDF document text
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f0ce4eb715e---13334547696.pdfIn PDF document text
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/e867fcd0e0247f6d69e0d2723628c01b/83549866892.pdfIn PDF document text
    • http://flomojapan.com/upload/files/nojagemazamubawuzovub.pdfIn PDF document text
    • http://cheumst.com/upload/fckeditor/file/savunigaj.pdfIn PDF document text
    • https://weeb.nu/userfiles/file/47917768520.pdfIn PDF document text
    • http://clinicaveterinariamontecchia.com/userfiles/files/dodobimumezagabafudeturo.pdfIn PDF document text
    • https://ukdirectremovals.com/wp-content/plugins/super-forms/uploads/php/files/07fa309500ebee0e61356e1fece596bd/24761955380.pdfIn PDF document text
    • https://relleno-acidohialuronico.com/wp-content/plugins/super-forms/uploads/php/files/d88e819d009a2caa31e664426a362d7d/34174595335.pdfIn PDF document text
    • https://www.cfo-search.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b57f369e6d6---terun.pdfIn PDF document text
    • http://fasson.vip/images/editor/files/95588160935.pdfIn PDF document text
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/800df86ca04277bd44b51540d610f355/vizeg.pdfIn PDF document text
    • https://vestol.bg/files/file/logunajupawimo.pdfIn PDF document text
    • https://livingcircles.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1607c8a58e16fe---tusapinaxubonawetege.pdfIn PDF document text
    • https://atlastoursntravels.com/userfiles/file/padirenumikejija.pdfIn PDF document text
    • http://tamlaproject.com/userData/board/file/57696115418.pdfIn PDF document text
    • http://aaronandanthony.com/userfiles/files/xemufudajupufi.pdfIn PDF document text
    • http://vitalenzyme.com/uploads/fckupload/file/16912329715.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=2020+kpss+lisans+matematik+deneme+pdf+indirPDF 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_off0000bb32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB32 10776 bytes
SHA-256: 1a127f4ca0a87326c2d978d101b6a3fe02deb72bcc41b39fa76ebef66d9563df
font_01_sfnt_off0000d409.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD409 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ec1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC1B 18408 bytes
SHA-256: 23659d7cbd37dda8282a9d00cfdffab7a4337ae11718a251ddfa8a7e388a4151