Malicious PDF — malware analysis report

Static analysis result for SHA-256 27d84638e97d132c…

MALICIOUS

PDF

89.5 KB Created: 2021-09-18 20:55:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 525e87e7066e628abb27214b225ea8d9 SHA-1: f4068d016da983adfbecb528b1f93df2d7bad71e SHA-256: 27d84638e97d132cddc14bd975f6efa56dd47e73f68b6d21077615299ccfa3eb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to other PDF files hosted on various domains, some of which appear to be compromised WordPress sites. The presence of 'utm_term' parameters in some URLs suggests an attempt to track user engagement with these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 https://bachson.net/upload/file/rudepador.pdf In PDF document text
    • http://heldermusic.nl/ckfinder/userfiles/files/xiwajujonizagusawon.pdfIn PDF document text
    • http://lifecare4all.com/upload/files/letigunaguz.pdfIn PDF document text
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137104d6acf4---savodukamopetor.pdfIn PDF document text
    • http://xn--9i1b14lwsg1seumdzsx.com/upload/fckeditor/file/tiponejovuzipukuboru.pdfIn PDF document text
    • http://aldo-ins.com/userfiles/file/77807913924.pdfIn PDF document text
    • http://ilturismoinitalia.it/userfiles/files/23679238696.pdfIn PDF document text
    • https://mayxaydungthienlong.com/uploads/files/files/sifowalonupadikukatedog.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/161429c230b5b6---rowibunojuviwaxula.pdfIn PDF document text
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/7hq9tudn9djdgsqoa5cjhfc0t1/rerusuwul.pdfIn PDF document text
    • http://www.kindytennis.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b8e139c3cb---61659624287.pdfIn PDF document text
    • http://nacyc.jp/Upload/file/25365146137.pdfIn PDF document text
    • https://nhuadailoan.vn/upload/userfiles/files/lopofesavomefutulibigok.pdfIn PDF document text
    • http://mineraux-et-lithotherapie.fr/ckeditor/upload/files/77890057184.pdfIn PDF document text
    • https://cdmsig.com/ckfinder/userfiles/files/68387074609.pdfIn PDF document text
    • http://energcomb.net/cms_enercomb/sgi_userfiles/userfiles/files/21397216945.pdfIn PDF document text
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b41e7d113d---vugofanofomebepipowegit.pdfIn PDF document text
    • http://gemwishrs.com/ckfinder/stones/files/2168924827.pdfIn PDF document text
    • https://dm288.rs/slicice/file/4386014749.pdfIn PDF document text
    • https://kawanmto.net/contents/files/debobelilisopon.pdfIn PDF document text
    • http://fgsconsulta.com.br/ckfinder/uploads/userfiles/files/xifudibil.pdfIn PDF document text
    • https://cissud.eu/uploads/ck_editor/files/pituromalipanobuberoza.pdfIn PDF document text
    • http://jedzenie365.pl/ckfinder/userfiles/files/76199272313.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=jak+usun%C4%85%C4%87+wirusa+na+androidziePDF 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_off0000f8ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8ED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011104.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11104 10800 bytes
SHA-256: 01d4891902865ed7ece2d7aedb90e18c534a71e560507fc82c3bcd4152f43ffa
font_02_sfnt_off000129cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129CD 17628 bytes
SHA-256: a6c1c9f6b6082f8fb57e23650bf39e0cc9421790c5abc17dc67963fb65c6cae0