Malicious PDF — malware analysis report

Static analysis result for SHA-256 3806515473e33d8a…

MALICIOUS

PDF

72.6 KB Created: 2021-09-08 02:57:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: a6799c4075d3df27fc968a2579e01982 SHA-1: 03e435c87e312a01620a9384c783220c13f32819 SHA-256: 3806515473e33d8a6d8503982f7926e00c917ff8782414b0e9acf7e2251681dd
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious. While no scripts were explicitly extracted, the nature of the embedded URLs suggests an attempt to direct users to potentially malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 5

  • 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.renfrewareahealthvillage.ca/ckfinder/userfiles/files/mafamak.pdf In PDF document text
    • http://calliopegoodrich.com/clients/73417/File/93614584908.pdfIn PDF document text
    • https://allianztc.ro/files/file/24505972397.pdfIn PDF document text
    • https://www.institutvzdelavani.cz/files/28481449834.pdfIn PDF document text
    • http://dichvutheapec.com/upload/FCK/file/86833232.pdfIn PDF document text
    • https://supermagnum-bg.com/ckfinder/userfiles/files/74015002257.pdfIn PDF document text
    • http://neo-net.info/giganet/files/file/nefutul.pdfIn PDF document text
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dfdbbabf1d2---naroxukodeze.pdfIn PDF document text
    • http://www.conectadoscomdeus.tv/arquivos/file/19368330556.pdfIn PDF document text
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/12f1f375fd62dd69e6439b89c133b69b/47535207647.pdfIn PDF document text
    • http://www.me.ntou.edu.tw/ckfinder/userfiles/files/20210803_192931.pdfIn PDF document text
    • http://n2nnetworks.com/files/others/73244565980.pdfIn PDF document text
    • https://goldenparadisestsimons.com/wp-content/plugins/super-forms/uploads/php/files/368fdf011334518a30b582c7d913f5da/fepogasikukoxoguvemugal.pdfIn PDF document text
    • http://lammensfilip.be/uploads/files/61013567465.pdfIn PDF document text
    • https://www.varisistanbul.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070a159c538a---66804467676.pdfIn PDF document text
    • https://namkhoasaigon.vn/web/images/files/pepetuzefugubopejow.pdfIn PDF document text
    • https://tasleemdubai.com/userfiles/files/68966047726.pdfIn PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/iuv6dv3kjd70r6fmkfd439ejab/nisiruvototuxibuwis.pdfIn PDF document text
    • http://mirutte.com/newsfiles/files/xipub.pdfIn PDF document text
    • http://blackivy.pl/userfiles/file/jovarawesavazododova.pdfIn PDF document text
    • http://slhospital.com/upload/fckeditor/file/16767872642.pdfIn PDF document text
    • https://cosalesrep.com/wp-content/plugins/super-forms/uploads/php/files/70b0224dcd4cae523d63a5433deb7cb1/6674706848.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=vance+and+hines+fuelpak+manualPDF 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_off0000b99a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB99A 10728 bytes
SHA-256: b1fd3a12aed611821fe0d35803e167f81c94469427f57a6ea944be3dab3af645
font_01_sfnt_off0000d200.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD200 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ea12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA12 16792 bytes
SHA-256: 6bdcae44db7d70889764c6d50216faafea4e0250219f11fc1f7377b1cdd23111