Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc6ac74b22cd315e…

MALICIOUS

PDF

81.4 KB Created: 2021-09-15 19:53:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 7e84f175552ad33e4d959b39fb4953ce SHA-1: 718a38df208ad2cf9aa18613f69aa01ac95d7a24 SHA-256: bc6ac74b22cd315e6bbc406761e88bc4dedd44f83d42b922a0843162f4a8b767
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for exploiting PDF vulnerabilities or redirecting users. The presence of multiple external links, including one pointing to compromised WordPress upload storage, indicates a link farm designed to direct users to potentially malicious content or phishing sites. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of its attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://proetcontra.hu/userfiles/file/11310133410.pdf In PDF document text
    • http://likuidart.com/files/ckeditor/files/wurajeruvarixopituvivutun.pdfIn PDF document text
    • http://popnmusic.fr/userfiles/file/jufipiverajikin.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/a3bcd3fe131df50ff944a33446733fe5/6215804341.pdfIn PDF document text
    • http://grafosaleservice.cz/images/fck_editor/file/mafefekubo.pdfIn PDF document text
    • http://eugensa.lt/app/webroot/uploads/userfiles/files/wovaraf.pdfIn PDF document text
    • http://zekejozsef.eu/FCKfeltoltott/file/nafejoxawezisesiw.pdfIn PDF document text
    • http://dianacb.cz/userfiles/file/folatipiwuzawani.pdfIn PDF document text
    • http://fratellibeninca.com/images/file/vesisep.pdfIn PDF document text
    • http://buddhavehicle.com/userfiles/file/lojovapedenivujigomitizad.pdfIn PDF document text
    • https://kawanmto.info/contents/files/vuzokali.pdfIn PDF document text
    • https://nhatngudongkinh.com/upload/ckupload/files/34250319632.pdfIn PDF document text
    • http://maduraicaterers.com/app/webroot/js/ckfinder/userfiles/files/xabavoli.pdfIn PDF document text
    • http://grubstreet.ca/ckfinder/userfiles/files/74237909705.pdfIn PDF document text
    • http://www.sas.edu.mn/ckfinder/userfiles/files/tumon.pdfIn PDF document text
    • https://fiberglasssupplydepot.com/userfiles/files/jafiwufikukeguvuvoke.pdfIn PDF document text
    • http://serting.eu/userfiles/files/piruzixativabotosukesedop.pdfIn PDF document text
    • http://miet-boot.ch/images/uploadedimages/file/poluwipodov.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/161326a03abba5---jezul.pdfIn PDF document text
    • https://remini.hu/userfiles/file/papozakepoxifamelozil.pdfIn PDF document text
    • http://aylabawadi.ae/userfiles/file/82632531627.pdfIn PDF document text
    • https://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/s07cfbnsu52fl642r04n9ch43s/96380877421.pdfIn PDF document text
    • http://ngocminhcnc.com/demo_thietbimay_24_7/upload/files/68865249382.pdfIn PDF document text
    • http://vistobrasil.net/uploads/file/duretul.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=how+to+copy+text+from+phone+to+pcPDF 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_off0000d9a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9A1 17832 bytes
SHA-256: 70d14f40e53b381a749e51201e58f0d18ca65bb223feb7f3c6b4b0ab50edf3f5
font_01_sfnt_off00010796.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10796 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011fad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FAD 10572 bytes
SHA-256: e82a904734791419a40b54a58950122d6cd900e1a2995972cb9abfbd941d3586