Malicious PDF — malware analysis report

Static analysis result for SHA-256 35f4d8f3167a8fa0…

MALICIOUS

PDF

96.0 KB Created: 2021-08-08 04:35:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 6afd063e9c800c013a956a7a527ed29d SHA-1: fb5bb4366f844193ca7fe10a61cd7c4046c9e16a SHA-256: 35f4d8f3167a8fa0a0c12712cd851db85addf4355e03a050b841196a4259ba70
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan payload. It functions as a link farm, directing users through multiple domains, some of which are hosted on compromised CMS uploads or disposable hosting. While no scripts were explicitly extracted, the PDF structure and heuristic firings suggest an attempt to lure users to external, potentially malicious, resources.

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://amctop.com/board_data/editor_img/file/202106030056.pdf In PDF document text
    • https://bczenekar.hu/files/file/lesototixepuvovawe.pdfIn PDF document text
    • https://mamproducciones.es/wp-content/plugins/formcraft/file-upload/server/content/files/16098c4eacc4d2---tepunegipexi.pdfIn PDF document text
    • http://szkolaprzybranowo.pl/ckfinder/userfiles/files/30642589555.pdfIn PDF document text
    • https://lightupalife.org.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160fc97321fddd---gejekemefukuwupezigege.pdfIn PDF document text
    • http://hoangle.vn/uploads/userfiles/file/kozivebowix.pdfIn PDF document text
    • http://studioingegneramato.com/userfiles/files/96989228011.pdfIn PDF document text
    • http://cambresisemploi.fr/ckfinder/userfiles/files/18850406557.pdfIn PDF document text
    • http://arohitourandtravels.com/userfiles/file/wegijujukevid.pdfIn PDF document text
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/160a6aae1d50eb---3365109184.pdfIn PDF document text
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/1c717c1b1661c79c4b1da18339b8d6c5/49049774907.pdfIn PDF document text
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607262428c15f---levowugowawefev.pdfIn PDF document text
    • http://beerskiboot.com/img/upload/file/metig.pdfIn PDF document text
    • https://www.m2asolutions.com/wp-content/plugins/super-forms/uploads/php/files/21ab4fee231fac0647d3ee25516da6f2/60098914488.pdfIn PDF document text
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c0684c75dbc---maxitigojapubalij.pdfIn PDF document text
    • http://www.cerathai.com/image/upload/File/tizekegizarofa.pdfIn PDF document text
    • https://nestsearch.in/admin/uploads/file/11307105812.pdfIn PDF document text
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607e95cac5e12---96474278756.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e874770f55c---fagozedudijozom.pdfIn PDF document text
    • http://adimhukuk.com/resimler/files/fabigojasot.pdfIn PDF document text
    • http://www.lentilles-progressives.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160760377e2795---mivivemosugu.pdfIn PDF document text
    • http://mrpokedb.com/uploads/files/52260367317.pdfIn PDF document text
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b0ce7a019ba---9164532899.pdfIn PDF document text
    • https://southafricapools.com/contents//files/23036769892.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=novelas+de+deseo+romanticas+descargar+gratisPDF 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_off00010982.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10982 10756 bytes
SHA-256: 0479af2638b8125ab7865c901f3872faa50b836c86f73628b489ddb295103aa6
font_01_sfnt_off00012206.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12206 20492 bytes
SHA-256: 0af80d8d4c7f52c9ef6e2059b793c97e9551499010e2746f142aeb371b26f64b
font_02_sfnt_off00015710.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15710 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1