Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb794c5b790fc4df…

MALICIOUS

PDF

81.1 KB Created: 2021-09-21 05:41:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: f76e72ce9ebe69ce206b5b48289d641d SHA-1: b4977764532306fba4dd0bf034879a90105e0bb8 SHA-256: cb794c5b790fc4dfc5970ec8dafbea57097d89dea86a7038a7ab29def4b5e983
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ClamAV and an ML classifier. It functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS platforms. The presence of embedded URLs and the nature of the link farm suggest an attempt to redirect users to phishing sites or download further malicious content. While no scripts were explicitly extracted, the PDF structure and URL patterns are indicative of a malicious lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://tainghe.vn/userfiles/file/walodiparonuvolizeded.pdf In PDF document text
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/7a2e96722c61e3e0050d711c1f608841/suvasenefaledol.pdfIn PDF document text
    • https://faktxeber.com/resimler/files/5112493459.pdfIn PDF document text
    • https://webrobogo.hu/kepek/74113334074.pdfIn PDF document text
    • http://yousefmaktabi.com/ckfinder/userfiles/files/lazobabanukotedulunoliv.pdfIn PDF document text
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/0beddf0fd044aa0fa74329267032c656/vegakofuzutaw.pdfIn PDF document text
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613e07a429a68---jajabojunom.pdfIn PDF document text
    • http://vizugy.hu/uploads/files/48763900124.pdfIn PDF document text
    • https://inmaabiladi.com/userfiles/files/87130604523.pdfIn PDF document text
    • http://islenapuntos.com/campannas/file/dijirato.pdfIn PDF document text
    • https://atlantidegattico.it/file/bimorog.pdfIn PDF document text
    • https://edenestates.com/ckfinder/userfiles/files/40994562182.pdfIn PDF document text
    • http://tajesink.com/Uploadfiles/files/68525831584.pdfIn PDF document text
    • http://phongkhamthienhoa.org/images/files/72372168101.pdfIn PDF document text
    • https://toananhmedical.com/uploads/files/rigukixopa.pdfIn PDF document text
    • http://salocchi.it/userfiles/files/2361595331.pdfIn PDF document text
    • https://sanagustin.cl/files/mijutozodixafi.pdfIn PDF document text
    • https://gemma.lucien-sv.info/uploads/files/613da2863f3d8.pdfIn PDF document text
    • http://okzawidow.pl/img/upload/files/9855797226.pdfIn PDF document text
    • https://i-try.tw/upfile/files/2021/09/07/figikiwojexovaxu.pdfIn PDF document text
    • http://rialta.ie/userfiles/files/dakipojilixezezebud.pdfIn PDF document text
    • http://www.temaricerca.com/entry2013new/admindia/ckfinder/userfiles/files/tifipojugifus.pdfIn PDF document text
    • http://xn--80aafkatcapceshpicpg3h.xn--p1ai/pict/file/17679682300.pdfIn PDF document text
    • http://permanentnimakeup-brno.cz/userfiles/files/91805401157.pdfIn PDF document text
    • https://tutorlookup.com/ckeditor/ckfinder/userfiles/files/25635076795.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=line+graph+in+excelPDF 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_off0000dabf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDABF 17236 bytes
SHA-256: f9ab9bbc4979e727f19e87ac757864face5d1eeec668d6cc808627bd375356f7
font_01_sfnt_off00010790.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10790 10328 bytes
SHA-256: 27f9252d9f5164663245502cb7c315c16871b8f472bb953b3bb49b560ce86e4f
font_02_sfnt_off00011eb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EB7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1