Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4bea765b884c93f…

MALICIOUS

PDF

82.7 KB Created: 2021-07-10 04:11:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: d6d4a7aba2c9e130e51af0fd579dc7cc SHA-1: b2dd334be73424a1ab0ce70a54b62b25f9d2f820 SHA-256: a4bea765b884c93fc802c4a6567006b43ffa288fda353235b4dd258c57ce654d
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting it's part of a link farm or SEO poisoning campaign. The ML classifier strongly indicates maliciousness, and the presence of external URIs points towards potential redirection to malicious content or phishing sites. No scripts were extracted, limiting the analysis of direct execution capabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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://cructi.ru/uplcv?utm_term=tasha+smith+for+better+or+worse PDF link annotation
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/dnd8umnfun2s0m0v2lttluself/konikixuje.pdfIn PDF document text
    • https://burragebrothers.com/demo/jolie/beta/userfiles/files/xijupuxaxerikevubi.pdfIn PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160bbad0852783---81679952985.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608db6b07b1c6---nurawogebilan.pdfIn PDF document text
    • http://a2itsolutions.com/chop/multimedia/userfiles/file/80210136584.pdfIn PDF document text
    • http://conservationenergy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ecafe03eb8---disaso.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160a93e6759bb7---dolaripuweritog.pdfIn PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/bmotc5tqrbukm8c7cvvkvu5i3g/83518757034.pdfIn PDF document text
    • http://briarcliff68.com/clients/71184/File/84644349417.pdfIn PDF document text
    • http://koreaseowon.com/ckupload/files/32303868817.pdfIn PDF document text
    • http://ahdongjiu.com/upload_fck/file/2021-5-22/20210522104505189407.pdfIn PDF document text
    • https://clumba-indoor.ru/files/files/23872456019.pdfIn PDF document text
    • http://vladjurnalist.ru/archive/file/4090698343.pdfIn PDF document text
    • http://bukharaalpharetta.com/sites/default/files/file/50523987751.pdfIn PDF document text
    • http://www.stallionreadymix.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160d0c75a811ae---pitolexalakoj.pdfIn PDF document text
    • http://run2endalz.org/clients/2/2b/2b4973775a35d8819257a28a16fdea67/File/29320129881.pdfIn PDF document text
    • http://geose.ru/userfiles/file/36003180748.pdfIn PDF document text
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608b45c0c5e36---tuzezu.pdfIn PDF document text
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609300dceb65c---79864172856.pdfIn PDF document text
    • https://fellowpeo.com/wp-content/plugins/super-forms/uploads/php/files/9b2e68ade96ffc35023d02456b343a49/tavogun.pdfIn PDF document text
    • https://delphin-restaurant.com/ckfinder/upload/files/58921591629.pdfIn PDF document text
    • http://foto-preiss.at/upload_files/files/48570423260.pdfIn PDF document text
    • https://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160cea6dc23711---peremadajumewaxeze.pdfIn PDF document text
    • http://lltsg.com/uploadfile/file///2021062007512625.pdfIn PDF document text
    • http://rorolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/fajanixo.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/50901612223.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_off0000df87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF87 17388 bytes
SHA-256: 9734aa2c45ad43ddd2ae1f20c1286a5099bdff08bdaccc117232c1b1b68b7122
font_01_sfnt_off00010d3c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D3C 10516 bytes
SHA-256: 506a6cc584c3d63fd814082d16d38fe032160201e499f0531c8517bbf0e00a36
font_02_sfnt_off0001254b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1254B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1