Malicious PDF — malware analysis report

Static analysis result for SHA-256 5bef53c99c67cd3a…

MALICIOUS

PDF

91.0 KB Created: 2021-10-08 00:59:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 2380896eba940c4b4e56d3ea3ba5b21c SHA-1: f2bea70713a94c78aa240371937da6f7b601eff4 SHA-256: 5bef53c99c67cd3af07311ac33e72bd4d0cf73ef94d9c6c32f36dc43f390f68a
96 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm or phishing lure. The ML classifier strongly flagged this PDF as malicious. The heuristics suggest the document is designed to redirect users to external sites, potentially for SEO poisoning or to host malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://irlanc.ru/uplcv?utm_term=chemical+formulas+and+chemical+compounds+chapter+7+review+answers PDF link annotation
    • http://sportsclinicwest.ie/media/contents/file/sewupade.pdfIn PDF document text
    • http://boxshop.mn/userfiles/files/likanadix.pdfIn PDF document text
    • https://vitanov.rs/files/59548205452.pdfIn PDF document text
    • https://kaptenhoki.org/contents/files/16366136724.pdfIn PDF document text
    • https://luxurybaths.marblobaths.ph/app/webroot/img/files/73329002304.pdfIn PDF document text
    • http://sgyscom.com/upload_fck/file/2021-9-13/20210913131854830875.pdfIn PDF document text
    • http://urgentcarepb.com/userfiles/file/roradogegab.pdfIn PDF document text
    • https://latework.cz/soubory/toput.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/8krdqqb2kvsc82sndk5in9j577/44897178214.pdfIn PDF document text
    • https://inchiriereelicoptere.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1615df2ad60c43---sijag.pdfIn PDF document text
    • https://xn--bren-mgenwil-gcbf.ch/sites/default/files/fck-uploads/file/balovubaxabevixuvod.pdfIn PDF document text
    • https://subarini.ro/mm/file/xatunasi.pdfIn PDF document text
    • http://abwrosedale.com/uploads/files/45458665847.pdfIn PDF document text
    • http://makesrealsense.com/ckfinder/userfiles/files/mufakuweferagor.pdfIn PDF document text
    • https://clinicaabrahaoosta.com.br/ckfinder/userfiles/files/95552867138.pdfIn PDF document text
    • http://bladensburg.abwingsmd.com/uploads/files/38900447907.pdfIn PDF document text
    • http://xn--2-140-swe8h.xn--p1ai/files/17788103781.pdfIn PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/161493ad736fec---mugufo.pdfIn PDF document text
    • https://recapress.com/ckfinder/userfiles/files/bixuxusukakozozobe.pdfIn PDF document text
    • http://sns.hu/_user/file/kigadazuzafabilutolew.pdfIn PDF document text
    • http://ustunongel.com/image/files/xerivibasusumebilevuwijuk.pdfIn PDF document text
    • http://www.homefacelifters.com/wp-content/plugins/super-forms/uploads/php/files/35a8ac8e0d4715c64bf6b0214aa2a18c/62852180031.pdfIn PDF document text
    • https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/a883d3208be27037b74244ac1b210ee7/pumiramomegulokoterinorar.pdfIn PDF document text
    • https://equipelec.fr/ckfinder/userfiles/files/depomuturulelesobijosevod.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_off0000f3f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3F1 21224 bytes
SHA-256: 31aab15fa8d78e7bff67b8e835f4f48888e29fe44566c1b434951c0f376db78f
font_01_sfnt_off00012b7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B7C 11220 bytes
SHA-256: 93f1c170a85af96b6f6c6e656c4ead0e79a3494356223006824badcc1c5b44d0
font_02_sfnt_off000145b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x145B9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1