Malicious PDF — malware analysis report

Static analysis result for SHA-256 fbcc31520761f986…

MALICIOUS

PDF

87.5 KB Created: 2021-08-18 08:05:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 9aa9896913fb84ae3311624f7103a718 SHA-1: 8785e29a4686a0c3f061ceb706a31867359c4af7 SHA-256: fbcc31520761f98669775e5775e557b39bedef7e3567859ba2551060c735f171
96 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to compromised WordPress installations or disposable hosting. This structure is indicative of a link farm, likely used to manipulate search engine rankings or to host malicious content. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

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://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae102e18afa---diziz.pdf In PDF document text
    • http://harmonie-avion.fr/actualite/files/negodox.pdfIn PDF document text
    • https://a5productions.com/home/a5pro/public_html/ckfinder/userfiles/files/414946039.pdfIn PDF document text
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/1608557f470344---liwapi.pdfIn PDF document text
    • https://tutorsbureau.net/userfiles/file/vofixarilufuzaguvekojum.pdfIn PDF document text
    • https://hohsingfiber.com/ufiles/files/22695644596.pdfIn PDF document text
    • https://djhelaly.com/wp-content/plugins/super-forms/uploads/php/files/b4d711f5ad471e488eea66d704e7f7f5/nupotawewuwinavuwudezoju.pdfIn PDF document text
    • https://cowichanseniors.ca/userfiles/file/40156112315.pdfIn PDF document text
    • http://ehsclassof88.com/clients/7/7f/7f6c4973f16106f9a1f2948091db50b4/File/kinakazunak.pdfIn PDF document text
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/aad3f76b0bf1b8c34c25cae11233f591/1693836958.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a58ea252296---xizawudetugujubivixuroma.pdfIn PDF document text
    • http://artikos.pl/userfiles/file/14411839671.pdfIn PDF document text
    • http://lbs.ac.at/wp-content/plugins/super-forms/uploads/php/files/b54u42sa0mjg8702a7p8pul7tr/semisenolop.pdfIn PDF document text
    • http://sistersaviopublicschool.com/userfiles/file/69491264315.pdfIn PDF document text
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/16071b6136be5a---biximafejulezavopivosuf.pdfIn PDF document text
    • https://earthideasawnings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f1ede24f79e---lewatonotefixevodoboga.pdfIn PDF document text
    • https://eletroluz-al.com/_IMG/img_internas/file/dized.pdfIn PDF document text
    • https://akarchlight.com/wp-content/plugins/super-forms/uploads/php/files/792d32751743a5d7f0beafefdeddc172/wexij.pdfIn PDF document text
    • https://afanasyev-design.ru/wp-content/plugins/super-forms/uploads/php/files/4567afd6879e1747b708b0cd060f3eb2/54265493719.pdfIn PDF document text
    • http://banglenhospital.com/UserFiles/File/54403606029.pdfIn PDF document text
    • http://cga82.com/admin/File/wojogup.pdfIn PDF document text
    • http://forter.vn/hinhanh/file/mulug.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/76e7039c00e6a67e689ef1fda4316993/36663280011.pdfIn PDF document text
    • https://ercrs.org/wp-content/plugins/super-forms/uploads/php/files/v7rcmijjtfa15umuthlipnh4ii/kavexaxeva.pdfIn PDF document text
    • http://dvg.asia/ckfinder/uploadfiles/files/lebopunabodib.pdfIn PDF document text
    • http://erbilsunhotel.com/wp-content/plugins/super-forms/uploads/php/files/0s6rn8q8bh4f4rbacb3lhhut17/33079093398.pdfIn PDF document text
    • https://euroroma-bg.org/files/file/jezotabusilososavoxiw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=is+it+normal+to+have+small+bubbles+in+urinePDF 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_off0000f32c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF32C 17300 bytes
SHA-256: ca896642d67c202816d7d01db202ebe1d73e9a389a4051f8dd1c80df92fd85dd
font_01_sfnt_off00011f7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F7B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013792.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13792 10628 bytes
SHA-256: 6568549542ac3e9fbbcc558b32fa85f0c1d7871e0a4a2e6a2c5452148c446eed