Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3382fa76516ebb9…

MALICIOUS

PDF

84.0 KB Created: 2021-09-01 15:07:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: fd4a20c92e1dd4fa7bcf17f1094d2d42 SHA-1: 4c659cfdbd766ccc4b393f84790d9dd28b0a5a3e SHA-256: b3382fa76516ebb9c3174ef34548d5fccf52bf6a2493e8cf25b1a75477f7fb72
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to compromised CMS upload directories, indicating it functions as a link farm. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery through these external links. The document body is unreadable, but the heuristic firings clearly point to a link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://www.vigo.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160d4ccec26ead---benanemisanani.pdf In PDF document text
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c76c68f2359---jubitovum.pdfIn PDF document text
    • http://www.anieliasfx.com/uploads/textareas/file/98275901013.pdfIn PDF document text
    • http://reclaimsplus.com/wp-content/plugins/super-forms/uploads/php/files/85f598bee163e5ea24c12338c6bf919c/rumumivise.pdfIn PDF document text
    • http://kepco-group.com/uploaded_files/userfiles/files/nitozivewafisopus.pdfIn PDF document text
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161160a68a2dbc---4076317407.pdfIn PDF document text
    • http://andreevmag.com/wp-content/plugins/super-forms/uploads/php/files/d3e8ba82d2510fd91dcbbbf3e97690ac/87244695568.pdfIn PDF document text
    • http://plafondchauffant.fr/img/user/file/77267488214.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ee2a238dfd8---vupexakakidonavegu.pdfIn PDF document text
    • http://melissajacksonmd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a781e8e260f---60152050886.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/q5e06b75nuuvgvqbr31hqccra3/bemuxi.pdfIn PDF document text
    • http://thuexe7cho.vn/upload/files/komalapa.pdfIn PDF document text
    • http://drsuthichai.com/userfiles/files/koruwixifojuxuzuvudud.pdfIn PDF document text
    • http://xn--22cjbbm2eyae3ehabdb4kqdtae3dxnnc1fhf.com/user_img/files/84156879709.pdfIn PDF document text
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1851990517---53165617542.pdfIn PDF document text
    • http://koovappadyscb.com/ckfinder/userfiles/files/lomivamujetusuj.pdfIn PDF document text
    • http://riverbendhay.com/clients/4/4e/4e1cbd84181290ddb66fb035c9950ff6/File/rezuwuwe.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/upu49o5a6qjkumchb2n3lrjh77/8652998950.pdfIn PDF document text
    • http://jcpingie.be/public/files/tikapulofubaxidexogi.pdfIn PDF document text
    • https://greenboo.vn/uploads/files/71634473032.pdfIn PDF document text
    • http://wongkungfu.ca/clients/f/f5/f5c316b966f29b3192b3e9e3c5714b3c/File/6509134690.pdfIn PDF document text
    • http://compsult.net/userfiles/file/momodesibo.pdfIn PDF document text
    • https://bazab.ru/ckfinder/userfiles/files/90047698100.pdfIn PDF document text
    • http://dent-pro.cz/pic/file/5054779439.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=best+high+school+swimming+statesPDF 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_off0000e738.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE738 10716 bytes
SHA-256: f6bcc79250021ef1e54463d95cd574ae8a3a3895aaa988c67c0baeedce4b42f1
font_01_sfnt_off0000ffc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFC3 16692 bytes
SHA-256: ad158a835a0348a6859de4861322b5e40f9cd63f18fb73419d23ab8e22b91ec8
font_02_sfnt_off00012ae5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AE5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1