Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9191ac3563dc8cf…

MALICIOUS

PDF

164.8 KB Created: 2021-07-02 18:00:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 1d466a6cee0f2a2a5077c7c6a5648ccb SHA-1: 9c99160dad9f89f8367984dc343ce678258c9cd8 SHA-256: b9191ac3563dc8cffbee2d891a33f3facd204faf421369a1fb4b970213b478f6
156 Risk Score

Malware Insights

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

The PDF contains a link farm directing to multiple compromised WordPress sites, which in turn host other PDF files. This suggests a phishing or malware distribution campaign where the initial PDF serves as a lure to further malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9903

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 http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/1609ca6c6a788c---1492721949.pdf In PDF document text
    • https://rybczewice.pl/userfiles/file/40889050413.pdfIn PDF document text
    • https://infravoip.com/wp-content/plugins/super-forms/uploads/php/files/58bad233aae608ae719fcbbdb2626ef0/2613681135.pdfIn PDF document text
    • https://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094cd46ab823---80972369857.pdfIn PDF document text
    • https://yournew.site/wp-content/plugins/super-forms/uploads/php/files/gbbnsc8jpfoa4kcuddv78bemmn/57442911578.pdfIn PDF document text
    • http://talleresjpg.es/img/file/43030166487.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d7261529e33---pelol.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/38092459806786c5838c196b8a4cdbb1/58161578914.pdfIn PDF document text
    • https://fobiy.net/wp-content/plugins/super-forms/uploads/php/files/2eba2c74474ac01ca5a7a4f1a316af2a/26025302712.pdfIn PDF document text
    • http://sonnenheizungen.ch/fckeditor/editor/images/file/nabawukazux.pdfIn PDF document text
    • http://pn-tech.net/userData/board/file/20209056767.pdfIn PDF document text
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160ac403d23f24---jovigobexigas.pdfIn PDF document text
    • https://hostmegasoft.com/calisma2/files/uploads/9911883527.pdfIn PDF document text
    • https://elitestrategyglobal.com/wp-content/plugins/super-forms/uploads/php/files/7db374f6203dffbf72124a644585771d/90160478476.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099ab43b2ca4---jamupexiruxonavudidifap.pdfIn PDF document text
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/4341c725ce76464b361600678c021a24/veburemopojep.pdfIn PDF document text
    • http://www.circoloaletrium.it/wp-content/plugins/formcraft/file-upload/server/content/files/160bfd7d39382b---kazawexonamijodetivo.pdfIn PDF document text
    • http://agendatourvietnam.com/hinhanh/file/14612984616.pdfIn PDF document text
    • https://www.traveltimevipp.com/wp-content/plugins/super-forms/uploads/php/files/9dcd05ec56c135bdcc415c2e48f26e63/96955904456.pdfIn PDF document text
    • http://brlairport.com/images/file/71180566618.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/1606ee347aca91---todotijadopag.pdfIn PDF document text
    • https://gdr.co.il/wp-content/plugins/super-forms/uploads/php/files/5a816a1c0097deecda97edb1c97a53fe/41762307285.pdfIn PDF document text
    • http://atmaircenter.com/lb/userfiles/files/tenozenuzatulop.pdfIn PDF document text
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/072abd16023ae6124c22ef7e7636ffaa/foxedojekomufidetapidiwos.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=paige+foster+and+tom+ryanPDF 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_off00022501.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x22501 18172 bytes
SHA-256: c8510d50718a3dc2035fa3ab6632923102bf29b2a7881b7a5831f8b2bfa0fea5
font_01_sfnt_off000254fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x254FE 10768 bytes
SHA-256: bbc9374837af77002bcf5600754eec83c8a52e00d1239076544e7c5e37c349bc
font_02_sfnt_off00026d9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x26D9E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1