Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f9cf631adf18f7f…

MALICIOUS

PDF

81.4 KB Created: 2021-09-02 23:12:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c8d394ff44aa38695c229d0fb9d3bb28 SHA-1: f93282688c7a7e8fbb500a256ac28f994f1377c9 SHA-256: 8f9cf631adf18f7f727b8bec7bca2a9d76c6a429b28c0c72784f00d281df0714
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains numerous links to external websites, many of which are hosted on compromised WordPress sites or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the presence of numerous URLs and the 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristic point to a malicious redirection scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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=social+judgement+theory+pdf PDF link annotation
    • https://esterkins.de/ckfinder/userfiles/files/sefigorotixuguwimurobel.pdfIn PDF document text
    • https://amursvoidom.ru/media/files/vujufurosavomojiju.pdfIn PDF document text
    • http://overtonnation.com/clients/f/f9/f97855507a39dfa58978186db9bff07a/File/74049555177.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/160acea78efad2---25569763104.pdfIn PDF document text
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16106df1037f06---68695321282.pdfIn PDF document text
    • https://napraforgohotel.hu/upload/file/fazujetuzazasasizulefiw.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16115e8616bc37---81433214435.pdfIn PDF document text
    • https://hirurgija.me//files/pilenavegimoza.pdfIn PDF document text
    • https://classykitchen.pl/web/uploads/files/29114740793.pdfIn PDF document text
    • http://e-pisanie-prac.pl/famprojekt_z_serwera/images/file/50367010200.pdfIn PDF document text
    • http://rlangkhan.com/upload/userfiles/files/bemirazetux.pdfIn PDF document text
    • http://vasilii-orlov.fun/wp-content/plugins/super-forms/uploads/php/files/2d133cde8af3db45601423449e79d64c/mupizupidawegikajesasowo.pdfIn PDF document text
    • http://kledingindex.nl/images/uploads/nosatozemi.pdfIn PDF document text
    • http://visusmarble.com/images_upload/files/momemofuzu.pdfIn PDF document text
    • https://www.taxiserviceh24.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609eac2ccdcca---15519984855.pdfIn PDF document text
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/16123667367076---wepezil.pdfIn PDF document text
    • http://svs-pm.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aada7d83628---99663289774.pdfIn PDF document text
    • http://ufnk.fr/app/webroot/files/file/witexatemelixerejobadi.pdfIn PDF document text
    • https://consultingexpert.eu/fckeditor/userfiles/file/wusafidu.pdfIn PDF document text
    • https://hondaotohaiphong.vn/upload/files/52105510241.pdfIn PDF document text
    • https://migger.dk/userimages/file/5785369429.pdfIn PDF document text
    • https://dehaventransportation.com/home/de/public_html/ckfinder/userfiles/files/28692336346.pdfIn PDF document text
    • http://ahsaipu.com/v15/Upload/file/2021542232483551.pdfIn PDF document text
    • https://traveltokiev.com/wp-content/plugins/super-forms/uploads/php/files/vc79tl5pec0gdnhbcsbcef8l92/duburazegogeg.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_off0000daad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAAD 16744 bytes
SHA-256: 5ab0867e989049eba4029f1088e99f23d8425338f8106b0cfdf9a052d68f12bb
font_01_sfnt_off000105b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105B0 11316 bytes
SHA-256: ff9f26f2bb60ea517866db497dfd7da18fd613e2ccd94a7b4bd4d81b84d4170e
font_02_sfnt_off00011fe0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FE0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1