Malicious PDF — malware analysis report

Static analysis result for SHA-256 544bb2762bba1c90…

MALICIOUS

PDF

84.4 KB Created: 2021-07-06 20:59:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 388bd55b68afb3171f4703fff8f4a1de SHA-1: 9b816f1f422eab9e40e690d2c8374ab2e9aefcfe SHA-256: 544bb2762bba1c9042ebf08742523298bc559475bd535453fda83245b6872b1f
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised CMS upload directories or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The document's structure as a link farm suggests it's designed to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://dentherapia.hu/files/file/zebajenodazegibakuzilamet.pdf In PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f86dcbf3a3---tusepiva.pdfIn PDF document text
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/9e4122f43aeeabb6d7e7877a33822563/38837658573.pdfIn PDF document text
    • http://ahsaipu.com/v15/Upload/file/2021429184552885.pdfIn PDF document text
    • http://clairerolo.com/userfiles/file/75768166022.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b2b7d92dab5---43831910906.pdfIn PDF document text
    • https://www.treehousecare.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607d680b0a333---97647194845.pdfIn PDF document text
    • http://scouttautomotive.com/editor_uploads/system/files/98181196133.pdfIn PDF document text
    • https://campermagazine.tv/public/file/638578181.pdfIn PDF document text
    • http://www.sandzthabapanel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a46612c32c9---widalili.pdfIn PDF document text
    • https://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/14a8230a5632acad62d9dcbd8872517b/verikulifofovurasod.pdfIn PDF document text
    • http://cpbnatation.fr/fckeditor/userfiles/file/55302672884.pdfIn PDF document text
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160bf2328651e7---jizatanotiweju.pdfIn PDF document text
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b861539b44---wodenikotebiga.pdfIn PDF document text
    • https://andrejc.si/files/file/wavokegebofuvafux.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/4539155804.pdfIn PDF document text
    • http://precedent.by/_newsite/images_from_html_editor/file/53685914760.pdfIn PDF document text
    • http://alphasigmaoverseas.com/userfiles/file/sapikovovizurixoxagede.pdfIn PDF document text
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/ac2da5s0u7q1a46p2kilab9841/90749596753.pdfIn PDF document text
    • http://raczcsalad.hu/files/95750308156.pdfIn PDF document text
    • https://www.inter-tube.co.uk/wp-content/plugins/super-forms/uploads/php/files/02de6e362808051ec8ad7b14f03e94f5/70527618002.pdfIn PDF document text
    • http://timavoshipsupply.it/userfiles/file/vajilatekufuvobegoj.pdfIn PDF document text
    • https://ludifrance.fr/userfiles/file/serowekidanevupisu.pdfIn PDF document text
    • https://mollis.rs//files/mexal.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/ig5556l0veg2rvpvgaf1h44km6/86536032039.pdfIn PDF document text
    • https://shoppingplanet.ro/ckfinder/userfiles/files/jelutobukapenevufa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=r+function+ifPDF 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_off0000eb44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB44 16620 bytes
SHA-256: 5d7963cb864a312028a5f6a48b04ce7cbc0c6970e6e2d468673855eba1100ebd
font_01_sfnt_off00011668.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11668 9868 bytes
SHA-256: ada6fa6a8ce8de1051f0b637a22eb739ec112fb43adebad833eb9b3b60a441f0
font_02_sfnt_off00012c3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C3F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1