Malicious PDF — malware analysis report

Static analysis result for SHA-256 c9f7757a779e102a…

MALICIOUS

PDF

81.2 KB Created: 2021-09-02 11:37:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 623da456c7af3aa482d2d2893c478be9 SHA-1: 827fea2a4a55718c6a43654dc8055c74248c3ef2 SHA-256: c9f7757a779e102a2528f2c0a02c65f0b44fcbb7c6185d4133386abc29767f14
164 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to compromised WordPress upload storage and other potentially malicious sites. The presence of a visual download button further supports a social engineering lure to trick users into downloading a payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://jfefood.com/wp-content/plugins/super-forms/uploads/php/files/74938f3a87a5804ef4d54ba908eb5968/nejoxiwoze.pdf In PDF document text
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/03f2057e58b37d66ed1a880cd2bc2f28/zubopebozimesomako.pdfIn PDF document text
    • http://mosvag.ru/img/lib/file/pivoxilaj.pdfIn PDF document text
    • https://aldurra.ly/images-editeur/img/file/36610233977.pdfIn PDF document text
    • https://www.uflo.edu.ar/ckfinder/archivos/documentos/lazoboveb.pdfIn PDF document text
    • https://skazkavdom.com/wp-content/plugins/super-forms/uploads/php/files/ac2b37bfca9fdf76b8266dfe5a709d28/fulowuv.pdfIn PDF document text
    • http://skybuildinfraprojects.com/uploads/17111807572.pdfIn PDF document text
    • https://shotclock.ca/wp-content/plugins/super-forms/uploads/php/files/78af3e5966fac99e55bfe2e5f353926b/61004966970.pdfIn PDF document text
    • https://bdaudit.ro/userfiles/file/12826166323.pdfIn PDF document text
    • http://www.k-24.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075617e82c7d---97938875082.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609026cd3b32b.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160824759cabbd---78639303354.pdfIn PDF document text
    • https://atlanthealth.com/wp-content/plugins/super-forms/uploads/php/files/0ea8b2ad64116ac57cea9b7762c8dd4a/waxogizopevuwijimatazajas.pdfIn PDF document text
    • http://akgikorea.com/file_upload/fck_upfile/file/nipufefibepudugabivob.pdfIn PDF document text
    • https://kfz-gutachter-oliver-schiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/160cfc0300fa7d---rutodemutiguses.pdfIn PDF document text
    • http://yaqeen-eg.com/userfiles/file/xubewulawuruvod.pdfIn PDF document text
    • http://davidhammerstein.org/userfiles/file/18422627979.pdfIn PDF document text
    • https://mytopics.it/uploads/file/volivozovuj.pdfIn PDF document text
    • https://xlux.vn/wp-content/plugins/super-forms/uploads/php/files/c8h9h8urlcs6urki0jek2okune/situmegeku.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e3903b2ac7---lakutumurodomilejo.pdfIn PDF document text
    • http://jowinbio.com/upload/files/202108241410081839.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/16123e0aaa3c46---62445982329.pdfIn PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/d86162b99be14dcf4125f7d2b71dca7a/92365991791.pdfIn PDF document text
    • https://swagath.co/new/ckfinder/userfiles/files/76244228827.pdfIn PDF document text
    • http://bygreenpure.com/userfiles/file/gelakijole.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=ip+class+11+ncert+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_off0000db20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB20 10404 bytes
SHA-256: 11760fb30cf37bed5eec1fcc8b0585a1a03c09768010d4bc46232bc2e1e92b98
font_01_sfnt_off0000f2ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2ED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010aff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AFF 17164 bytes
SHA-256: a380543c6de0ba9e4ea1c348ed46f2b84c41069f5512f24e4cd38901c0815116