Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1bce3d4063f6921…

MALICIOUS

PDF

86.6 KB Created: 2021-09-20 15:02:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 4b3f22e65b4bf540222f3430c0e7960d SHA-1: 83ed74e005e6730a67dc88da747a92f7722f46b8 SHA-256: c1bce3d4063f69211e714069ba447013e8734bc06af55f8cb48ca9c7f3df3aba
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which point to disposable hosting or compromised WordPress sites, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the nature of the PDF and its numerous external links align with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://oniceh.ru/uplcv?utm_term=free+download+games+for+samsung+galaxy+s+duos+gt+s7562 PDF link annotation
    • http://jafra-com.at/userfiles/file/10428326905.pdfIn PDF document text
    • https://emotionalgift.com/ckfinder/userfiles/files/41398064234.pdfIn PDF document text
    • https://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/9473a62c1eee0ed9efacb78486d2b4ca/tijunomaza.pdfIn PDF document text
    • https://korzo-galeria.hu/files/file/naxakevewerep.pdfIn PDF document text
    • https://ispartaprefabrik.com/ckfinder/upload/files/gojodimuzizonetaselum.pdfIn PDF document text
    • http://urparitet.ru/admin/ckfinder/userfiles/files/78011865400.pdfIn PDF document text
    • http://www.logistiekverbeteren.nl/ckfinder/userfiles/files/42192440499.pdfIn PDF document text
    • http://studiobaliva.eu/userfiles/files/90919952404.pdfIn PDF document text
    • https://jordan.si/dokumenti/file/5140638474.pdfIn PDF document text
    • https://hanyauntuktesting.com/contents/files/kuwilosusasuzasafini.pdfIn PDF document text
    • http://tulga.ru/editor/files/xaxubirizunuwejulaxunok.pdfIn PDF document text
    • https://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/79c7bee699580afcd552c174fe9e5daa/xovisitolepefulubetogitoj.pdfIn PDF document text
    • http://njxinbell.com/upload/files/legawadisiwexe.pdfIn PDF document text
    • https://asiahealth.standrewsdentalsurgeons.com/ckfinder/userfiles/files/zaloparufidowizogonug.pdfIn PDF document text
    • http://likuidart.com/files/ckeditor/files/jemulavodoremupekelufoja.pdfIn PDF document text
    • http://studiofantino.it/userfiles/files/gutadun.pdfIn PDF document text
    • http://harckocsik.hu/userfiles/file/2707918848.pdfIn PDF document text
    • http://resortvillairene.it/userfiles/files/61141875796.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/16143221d92b59---18118128079.pdfIn PDF document text
    • https://lrsinc.co/userfiles/file/65774294929.pdfIn PDF document text
    • https://sanmuabancongty.vn/images/content/files/solapotilawefez.pdfIn PDF document text
    • https://ghnservizi.com/file/fokodakosalovitoj.pdfIn PDF document text
    • http://lamay.de/userfiles/file/lotutogiximixumonol.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_off0000e994.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE994 11456 bytes
SHA-256: 0f6e1c66987ab37b6e53a8cb71cd83de8abe26bf19decff5a6211116569c913e
font_01_sfnt_off000104b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104B8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011cca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CCA 18192 bytes
SHA-256: 898cb063b40976f4a42b5bf4b1db7dcaa38da5d036411ae6053b91233215b854