Malicious PDF — malware analysis report

Static analysis result for SHA-256 e836b815abad21d9…

MALICIOUS

PDF

160.0 KB Created: 2021-07-15 12:41:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 3f0ebccafcf32a45d8d1d95505c65aae SHA-1: 73a8c2d0c97ea43afa33d43ae088dfd0d1f1f633 SHA-256: e836b815abad21d943758d55462e07a97141033238224c8fe737271572290798
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to compromised WordPress sites and other PDF files, suggesting an attempt to distribute further malware or engage in phishing. The presence of multiple links on disposable hosting and the use of UTM parameters further support this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9903

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://thesaddlebank.com/wp-content/plugins/super-forms/uploads/php/files/f4ovgkjhgdvr6p8catf1o9cg5s/46828922966.pdf In PDF document text
    • https://performanceltg.com/wp-content/plugins/super-forms/uploads/php/files/f333d65c1eb554ab77e71bc4ece154f3/lizav.pdfIn PDF document text
    • http://yanartekstil.com/firma/files/gixuregudujebolu.pdfIn PDF document text
    • http://archi1919.com/smlclub-files/file/vawimonaxafir.pdfIn PDF document text
    • http://www.emporiocaritaspisa.it/wordpress/wp-content/plugins/formcraft/file-upload/server/content/files/160989f31ba083---logajawekimotufepitu.pdfIn PDF document text
    • http://sitoad.com/bbqjoekey/files/202106201811292448.pdfIn PDF document text
    • http://phuwangnam.com/user_file/file/52669005872.pdfIn PDF document text
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/45f2883db522f275673a409137de8887/65265717904.pdfIn PDF document text
    • https://gencshoworganizasyon.com/upload/ckfinder/files/lurizesatogalonijo.pdfIn PDF document text
    • http://scro.ru/pic/file/4445521978.pdfIn PDF document text
    • http://rockhouseschool.com/rockhouse/uploads/files/buripox.pdfIn PDF document text
    • http://hasici-pristroje-eshop.cz/files/file/ritivubolejamizutapu.pdfIn PDF document text
    • http://armanetti.com/images/fawutetuke.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c961099ef5f---rukaloxete.pdfIn PDF document text
    • https://www.mysmilestudios.com/wp-content/plugins/super-forms/uploads/php/files/f5ed694defbc218999b19f503e7e7123/18482210090.pdfIn PDF document text
    • http://banghetretunhien.com/media/ftp/file/55040005170.pdfIn PDF document text
    • http://geology.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160a7f32a1d553---tererin.pdfIn PDF document text
    • https://www.cibaospalaser.com/wp-content/plugins/super-forms/uploads/php/files/fsn5r5tbm3bm94k5o8ugsnntlg/fuxumenazoza.pdfIn PDF document text
    • https://dutchfansitenetwork.nl/ckfinder/userfiles/files/duvubasusapenetesugefuxi.pdfIn PDF document text
    • https://enville.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082511113248---40764775101.pdfIn PDF document text
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16077d8493379e---rojevosonafapupofi.pdfIn PDF document text
    • https://hasekei.jp/userfiles/file/sivubidomoxijoda.pdfIn PDF document text
    • http://halvani.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7a7ee8c3d5---jejilixisi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=in+medieval+timesPDF 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_off0002103d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x2103D 19556 bytes
SHA-256: 6390720d47250cb00895254fdb4f1dde34afe08fec75ae145052f0d2912887b4
font_01_sfnt_off00024257.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x24257 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00025a6e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x25A6E 10204 bytes
SHA-256: f48938b02de5da09ecaf6564624b8012ed1c83d772500a5275f7488973d6db14