Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca515955816d541c…

MALICIOUS

PDF

71.8 KB Created: 2021-08-26 03:49:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: ea6f679fd1ff1485cdcbcc47d364847c SHA-1: 6e30125773bb8414b8bfd9797b019fe91cd7ca0a SHA-256: ca515955816d541c27dcf50086454634d53cc4c47bbb786572aab0315364e8a2
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external URIs and is identified as a link farm, with many links pointing to compromised CMS uploads and disposable hosting. The ML classifier strongly indicates maliciousness. While no scripts were extracted, the structure and numerous links suggest a malicious intent, possibly to distribute further malware or engage in SEO spam.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://wastran.ru/uplcv?utm_term=mcgraw+hill+geometry+book+answer+key PDF link annotation
    • http://wu-pao.com/upfiles/editor/files/10469252205.pdfIn PDF document text
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099b0edc4018---18649668439.pdfIn PDF document text
    • http://stellamaris.cz/userfiles/dixagoxo.pdfIn PDF document text
    • https://agrilaui.com/userfiles/file/29213262129.pdfIn PDF document text
    • http://bean2beenefamilytree.com/clients/60578/File/fijamum.pdfIn PDF document text
    • http://www.deco-interieure.com/userfiles/file/rexazexaxesiz.pdfIn PDF document text
    • http://robedecreateur.com/img/files/romezeruzobupasi.pdfIn PDF document text
    • http://monktonlionsclubkidscamp.com/clients/9/99/99b8b5517e5fb663501b7ee5137ebf55/File/77977054683.pdfIn PDF document text
    • http://kondicionery-vidnoe.ru/upload_picture/file/98587561309.pdfIn PDF document text
    • https://lightsourceindiana.com/wp-content/plugins/super-forms/uploads/php/files/cdbee786fbc0c3a6f86a60736b0cc873/babazalixomerawaw.pdfIn PDF document text
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1611aac5989960---83609182390.pdfIn PDF document text
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/16079210c06247---83107311876.pdfIn PDF document text
    • http://szintai.hu/ckfinder/userfiles/files/xatuxosoziku.pdfIn PDF document text
    • http://anhuifan.com/upload_fck/file/2021-4-28/20210428210718485931.pdfIn PDF document text
    • http://newbiesites.com/userfiles/file/77954482036.pdfIn PDF document text
    • http://magogaralbamoble.com/galeria/files/54313280073.pdfIn PDF document text
    • http://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/16072f49cbacd5---81973482066.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/1607063d5595f1---moror.pdfIn PDF document text
    • http://trackeg.com/en/wp-content/plugins/formcraft/file-upload/server/content/files/160a03616da449---40924647528.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/cm668j5tavn5fjmuvoa9ro2i70/24434091724.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b2f52e47776---84335880970.pdfIn PDF document text
    • http://satthachkhe.vn/image/file/punumudetawusot.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_off0000b7db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB7DB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cfed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFED 15496 bytes
SHA-256: 505d3c71aca0291e8fba1c2d55768697f11084ae23edce25897945f6d1de518b
font_02_sfnt_off0000f79d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF79D 11104 bytes
SHA-256: b2d521747833a9fa7bcfb5ad377ac8f4dd2f2cc312c3405a5b86abdc61688284