Malicious PDF — malware analysis report

Static analysis result for SHA-256 70b2a8efd40ece39…

MALICIOUS

PDF

76.5 KB Created: 2021-09-14 09:32:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 09bc6a77df52d3d7733b3f1b37c02f1a SHA-1: ad6ae7f23f6768d148e47d0731783eed03cc8fdf SHA-256: 70b2a8efd40ece39cbaca5edc6ae9c84dded3e1cd836ddfde41b08f8a48b457b
96 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised or disposable domains, indicating a link farm or redirection scheme. The ML classifier strongly flagged this PDF as malicious, and heuristics identified it as a link farm on disposable hosting and pointing to compromised CMS uploads. The document body is heavily obfuscated and unreadable, suggesting it is not intended for human consumption but rather to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://archism.ru/uplcv?utm_term=suicide+squad+game+ios PDF link annotation
    • http://thuocnam.xyz/images/files/15288733628.pdfIn PDF document text
    • http://www.egymast-segito.hu/uploaded/fck/file/53218313887.pdfIn PDF document text
    • https://morganmethod.tuesdaytrader.com/ci/userfiles/files/pikezojetimagutijipijalig.pdfIn PDF document text
    • http://atut-biuro.com/uploaded/file/sixoperivewowotubakip.pdfIn PDF document text
    • http://www.psoealora.es/ckfinder/userfiles/files/27900693206.pdfIn PDF document text
    • http://diplomat2014.ru/ckfinder/userfiles/files/gevubexaw.pdfIn PDF document text
    • https://cvsc.co/userfiles/file/sigokebilexotabobejano.pdfIn PDF document text
    • http://oris-am.com/editor_up/11461053740.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161403374192a6---36935807162.pdfIn PDF document text
    • https://primeodontorj.com/wp-content/plugins/super-forms/uploads/php/files/c86f983c358d42c6265bb788a6714fa6/72303925896.pdfIn PDF document text
    • http://www.asap-recruitment.net/upload/file/56778001393.pdfIn PDF document text
    • http://vagtteam.dk/userfiles/Files/62797021088.pdfIn PDF document text
    • http://ciba.lv/uploaded/file/tebivakajumuzedikopodasal.pdfIn PDF document text
    • http://cieplej.pl/imgturysta/file/dalorinotolusosa.pdfIn PDF document text
    • https://jogamiskolc.hu/ckfinder/userfiles/files/3791186195.pdfIn PDF document text
    • https://rjiminfra.com/wp-content/plugins/super-forms/uploads/php/files/2550ff7cbe4d9739aad22aa12ff8225d/41443245339.pdfIn PDF document text
    • http://bc-arman.kz/ckfinder/userfiles/files/23614600258.pdfIn PDF document text
    • http://robalton.es/Albums/images/file///wajepawuz.pdfIn PDF document text
    • http://airmon.hu/images/files/56654046285.pdfIn PDF document text
    • http://bargiel.com.pl/ckfinder/userfiles/files/19134320094.pdfIn PDF document text
    • http://desiaussies.com/ckeditor/uploads/files/kubilusovusesepes.pdfIn PDF document text
    • http://bangdientunhk.com/upload/files/mubibanifo.pdfIn PDF document text
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/4eb2c58fa203169c3579b0429bd3cdf7/bazakakijebexi.pdfIn PDF document text
    • http://www.radio-kum.si/data/files/44981224541.pdfIn PDF document text
    • https://tadimtursu.com/image/files/21190705214.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_off0000c59c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC59C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ddb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDB3 10688 bytes
SHA-256: 3820893b20eb3cef05af9ad624f9ca280962de04609761bd76a846b84291f197
font_02_sfnt_off0000f5ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5AE 17944 bytes
SHA-256: 86e2d8346874b07597b5b5c4ec92afe7a4125f18da498d89b23d75297096b158