Malicious PDF — malware analysis report

Static analysis result for SHA-256 86f4883410f861d2…

MALICIOUS

PDF

76.0 KB Created: 2021-09-06 16:57:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: e90358236625661fdf1a56f07d45cc7e SHA-1: b81099e58720c45e60973efb39b05347da300de5 SHA-256: 86f4883410f861d2a00e357354cc7158d328383d32c734952c772c596978859c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF containing numerous links to external websites, many of which are hosted on compromised WordPress sites or disposable domains, suggesting a link farm for phishing or malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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=general+caste+reservation+form+pdf PDF link annotation
    • https://aristi-trap.com/upload/users/files/visowekatetapa.pdfIn PDF document text
    • http://wooshin.kr/uploaded/file/99769355660c4543a09340.pdfIn PDF document text
    • https://okazionche.com/files/42155849568.pdfIn PDF document text
    • https://wccia-vastu.com/wp-content/plugins/super-forms/uploads/php/files/a473157a153307ec9a9763092a6ec81d/55691314678.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16119f31932127---wekixib.pdfIn PDF document text
    • https://414movement.com/wp-content/plugins/super-forms/uploads/php/files/e2b5c40f4b83e76c612a4fa789d89464/wejude.pdfIn PDF document text
    • http://neurooperations.com/ckfinder/userfiles/files/48783440094.pdfIn PDF document text
    • https://www.harasportcenter.com/wp-content/plugins/super-forms/uploads/php/files/otv1s62av51v1gn2dhpt2jo4bg/87833596041.pdfIn PDF document text
    • http://uekekb.ru/!upload/files/85725683731.pdfIn PDF document text
    • https://www.taxikladis.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160b8ad67bce6f---13934970286.pdfIn PDF document text
    • http://asustainable.com/global/file/26308923998.pdfIn PDF document text
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/7i1t1c1nct3lnvnviobihegmfq/25904376767.pdfIn PDF document text
    • http://aite-materials.com/upfiles/file/jogaxiji.pdfIn PDF document text
    • http://a-aqua.fr/ressource/site-image/files/5220886154.pdfIn PDF document text
    • http://josephpowellfamilyreunion.com/clients/0/04/04c15d356d3082020e114f8c0300f46e/File/wodolewuselemowatufewe.pdfIn PDF document text
    • https://giraffeng.net/infodaily/gen-ckfinder/userfiles/files/mikopuganefan.pdfIn PDF document text
    • http://bennyhigh73.com/clients/3/33/33ce00c6a031cf3b17a3dcf69aaa7594/File/92979092621.pdfIn PDF document text
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/l8gj7e3mq017e10vi6clib5le5/bezonelubusofo.pdfIn PDF document text
    • https://erinmillssmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/eb9n0o0hq9mn23df5rjs7s77g4/sapuferelupilote.pdfIn PDF document text
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/160df01fa50c72---90677979819.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/16090e4b494678---kuludejuz.pdfIn PDF document text
    • https://estigotours.com/wp-content/plugins/super-forms/uploads/php/files/2ce5da18538022ed2689ecf171728e56/22855520841.pdfIn PDF document text
    • http://simsvizag.com/contentimages/file/nofunabalisaviwutejave.pdfIn PDF document text
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/e336ee0da4dea692e7b3c03d885e1beb/15478388642.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_off0000c5c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5C6 10888 bytes
SHA-256: d2b8e957a245344ac6d3c5db3b5ba7a12dda48ac9f33639e984adebc576d6af9
font_01_sfnt_off0000defa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEFA 16908 bytes
SHA-256: 0d77ad0b16de963796d5e2c9e914852a1a08bc982fa2f1641d228ec1cc4a94e4
font_02_sfnt_off00010a79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A79 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1