Malicious PDF — malware analysis report

Static analysis result for SHA-256 28597542d91dec9f…

MALICIOUS

PDF

84.1 KB Created: 2021-09-06 11:56:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 30e91bf6d485eee3b2b869115e23b906 SHA-1: 153374a8c0f47a89e72baef0fefe6ea18a4fdd44 SHA-256: 28597542d91dec9fcc4fd4f6be563c5d1e4551d769ac16af286d55d47f977780
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains a link farm pointing to various domains, many of which are hosted on compromised CMS platforms or disposable hosting, suggesting an attempt to distribute malicious content or phish users. The presence of embedded URLs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicate a redirection strategy. No scripts were extracted, but the overall structure and heuristics point to a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/5f2d1b707b624eaac267167369faee39/42472628647.pdf In PDF document text
    • http://bulmarconsult.com/files/dotekamide.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/85c7f09261c99a79397adf18c5cd8f79/30948514792.pdfIn PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a92f114c53f---vusitapumexubiwuxu.pdfIn PDF document text
    • http://prefinancovaniehypoteky.sk/res/file/53540930870.pdfIn PDF document text
    • http://wangyiphk.com/userfiles/lufilop.pdfIn PDF document text
    • https://massagetheory.ca/wp-content/plugins/super-forms/uploads/php/files/22d1ca231d3b122b6ae722a6af85c30b/mezimipiruvi.pdfIn PDF document text
    • http://karimeh.com/public/userfiles/file/duronatezimo.pdfIn PDF document text
    • http://domesticsolutionsagency.com/userfiles/file/puridelaj.pdfIn PDF document text
    • https://aulacvn.com/upload/fck/file/74049281756.pdfIn PDF document text
    • http://wagnerfamilyreunion.com/clients/866685/File/mosajuxagizunagajodozone.pdfIn PDF document text
    • http://feach.ie/images/uploads/file/58182286768.pdfIn PDF document text
    • https://www.dekleinewerf.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607f82145de2c---12615026583.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609908a3f3268---geziminivebej.pdfIn PDF document text
    • http://daiduongmetal.com/uploads/ckfinder/files/99589152044.pdfIn PDF document text
    • http://engroupe.ca/aym_image/files/nadapitumaxogid.pdfIn PDF document text
    • http://lineshare.net/upload/files/20210620061849.pdfIn PDF document text
    • http://minhphucvietnam.com/uploads/userfiles/file/5614319348.pdfIn PDF document text
    • https://jakspravnenapsa.cz/userfiles/file/94570976742.pdfIn PDF document text
    • http://teechart.com/uploads/images/files/42910532035.pdfIn PDF document text
    • http://asesoriagarpe.com/wp-content/plugins/formcraft/file-upload/server/content/files/160adbbd28ecfb---garafago.pdfIn PDF document text
    • http://cohensevents.com/clients/74638/File/xegepoxajaparogogijexew.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/cba8fc2bf2ccfee190ea5a91a7b170b0/netejepigebotutipotatok.pdfIn PDF document text
    • http://martonelektro.hu/files/file/bomuwoxubojodagetewixef.pdfIn PDF document text
    • https://alteanetworks.fr/img/file/kapagobomo.pdfIn PDF document text
    • http://uzks.hr/upload/datoteke/zodunikilupefeveka.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=projection+system+in+gis+pdfPDF link annotation
    • 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_off0000e26d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE26D 11000 bytes
SHA-256: d523ee3b5d67835d5188a64bf86a68663a3d7b9ba78e30d04f2a5adbe0270f82
font_01_sfnt_off0000fbbe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBBE 17848 bytes
SHA-256: f0e06b1c4fc790b35e22f1cc05070609366c71aea796fdc94e896bd702c2173b
font_02_sfnt_off00012a79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A79 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1