Malicious PDF — malware analysis report

Static analysis result for SHA-256 b21a853d724a9629…

MALICIOUS

PDF

86.8 KB Created: 2021-09-06 10:18:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: ed2bc07b08d9987bcc51fd514e11fd49 SHA-1: 51e51bc607f18d4fbc7d9135c4c475c172fe9698 SHA-256: b21a853d724a96290fbf57fdb672f4c2f435ff39cc3d3cdc0429aab077caf36a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection for 'Pdf.Phishing.Trojan'. The document functions as a link farm, containing numerous URLs pointing to potentially compromised websites or disposable hosting, suggesting an attempt to redirect users to malicious content. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://www.ideakliniksisli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611d5a2f0a8be---74877901196.pdf In PDF document text
    • http://s8radziejowice-paszkow.pl/userfiles/file/lujaxamefovevadop.pdfIn PDF document text
    • http://ibookingkr.com/FileData/ckfinder/files/20210901_96FE0F2264EDDE64.pdfIn PDF document text
    • http://calhi1974.com/clients/46234/File/98260441798.pdfIn PDF document text
    • http://grani-tonkogo-mira.ru/wp-content/plugins/super-forms/uploads/php/files/6ce37d8d9216b5c89d2cf09f88b77d49/82194466931.pdfIn PDF document text
    • https://fjordancv.info/wp-content/plugins/super-forms/uploads/php/files/c4133fa1a0de1f28da1fac174d5fe759/35061323424.pdfIn PDF document text
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160abef5ede579---45194930653.pdfIn PDF document text
    • http://perfectthesale.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081c486639a9---folagaxu.pdfIn PDF document text
    • http://bioterapiazabiegi.pl/obrazy/file/43487942025.pdfIn PDF document text
    • http://www.hptindia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f6c2cd4fcd6---nigiguburulaxejapixosuwu.pdfIn PDF document text
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/16085e96662d14---61948819292.pdfIn PDF document text
    • https://scalper.ir/data/files/file/poluxijemadi.pdfIn PDF document text
    • https://amursvoidom.ru/media/files/dobem.pdfIn PDF document text
    • https://isabellepieman.com/userfiles/file/53711484150.pdfIn PDF document text
    • http://md-servicios.com/userfiles/file/35863674052.pdfIn PDF document text
    • http://merrygoldholidays.com/ckfinder/userfiles/files/tenenogawefetuxu.pdfIn PDF document text
    • https://luxmarketing.agency/wp-content/plugins/super-forms/uploads/php/files/1252ba2gljfh2rfv971vbebj5l/vujemegoxet.pdfIn PDF document text
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/gs6hcpuqqfnbm0082ba1j033sv/fivosupukuvopi.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610488fcc0896---jimunojiluzapon.pdfIn PDF document text
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c7ac4b15bba---33555740104.pdfIn PDF document text
    • http://nguyenxuanhuong.com/upload/files/wiripumofisubudixitu.pdfIn PDF document text
    • https://jackinthegymtpe.com/uploads//files/202108072233336826.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=shark+euro+pro+steam+cleaner+manualPDF 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_off0000eca2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECA2 10812 bytes
SHA-256: 62070bf93d82d373dfed44de5a40d569e5d1413282de3966fe4700c2f67f32dd
font_01_sfnt_off00010572.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10572 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011d84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D84 18252 bytes
SHA-256: b0ab3f8c3ea460d56dae2033244ba217ffbd896d1a4aa1b685b18fe0b83521a2