Malicious PDF — malware analysis report

Static analysis result for SHA-256 271b6725a45e65a5…

MALICIOUS

PDF

74.0 KB Created: 2021-06-29 09:07:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: e779983ee1ebcc66fbfe9dc886d6cc01 SHA-1: 82eb5b971acc1d109c3e42faee1ccd452213396f SHA-256: 271b6725a45e65a583683e6e70f638950aa3485f12aa872d666eccb96e0bc5ff
96 Risk Score

Malware Insights

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

This PDF file contains a large number of external URIs, many of which point to compromised WordPress sites. The ML classifier strongly indicated maliciousness, and the structure suggests a link farm designed to redirect users to potentially harmful content. The presence of multiple compromised CMS upload links further supports the malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://krisoc.ru/uplcv?utm_term=and+or+c%23 PDF link annotation
    • https://mindweave.co.uk/wp-content/plugins/super-forms/uploads/php/files/n2bd5usetgehej60c51ma489ea/5439320825.pdfIn PDF document text
    • http://www.gametimecatering.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f7f910d72f---96107524384.pdfIn PDF document text
    • https://sindonis.com/userfiles/file/vilalupup.pdfIn PDF document text
    • http://www.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ae4f5cb267---buxiv.pdfIn PDF document text
    • http://beepost.vn/upload/userfiles/files/36097395123.pdfIn PDF document text
    • http://ceramicaartisticamarsalese.it/userfiles/files/26801448984.pdfIn PDF document text
    • https://dildendilecevirievi.com/upload/ckfinder/files/75007352890.pdfIn PDF document text
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/1609a711fa2da6---voduviza.pdfIn PDF document text
    • http://agapetown.net/ckfinder/userfiles/files/vukakidukig.pdfIn PDF document text
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/46uh7i1l0fsdc81gjvrnpksnue/jubofonatuvaposisid.pdfIn PDF document text
    • http://itaindustrial.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c72bfd2ae52---wotaginen.pdfIn PDF document text
    • http://gentlemensquartersbarbershop.com/wp-content/plugins/super-forms/uploads/php/files/72f6becbb1f8121f4f100447245ee221/2392465498.pdfIn PDF document text
    • http://teusz.pl/UserFiles/file/57363208126.pdfIn PDF document text
    • https://arihantgranites.in/wp-content/plugins/super-forms/uploads/php/files/fkk3qk5jih0nl7bovvh8t64em7/wavetilotaviwovot.pdfIn PDF document text
    • https://stollerco.com/testingsites/advantage_aviation/assets/media/file/nizexitanidufidorevu.pdfIn PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/e167e654a71884ce660a2dbceaa9ca97/xekizelewivirefe.pdfIn PDF document text
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/dff771bb066fb02411ae245cd43d69db/baxururad.pdfIn PDF document text
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e79ca14eda---52937651670.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d4ffc3e45a---77073776063.pdfIn PDF document text
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/d473972dc7af7232b5267859032180df/xuxupewefujamafevi.pdfIn PDF document text
    • https://blackknowledge.com/wp-content/plugins/super-forms/uploads/php/files/8e8ba29501f702eeb909c49de09e234b/61365623149.pdfIn PDF document text
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1607a33501550d---bebagidarimoxiberopun.pdfIn PDF document text
    • https://topclassgardening.nl/images/file/vijifavaxuk.pdfIn PDF document text
    • http://usaoxin.com/userfiles/2021-5/file/36916371317.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_off0000c2e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2E3 16436 bytes
SHA-256: b24668138c6df4838ba110c4a3608676955da2fe50145a2f32b0a1d7e267e7db
font_01_sfnt_off0000edd1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDD1 9648 bytes
SHA-256: 93636a365f86bab450fc1aa1ad541faf6575fc4f9619b226aafa439f9665f304
font_02_sfnt_off000102cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102CD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1