Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3cbe26c5655b6bd…

MALICIOUS

PDF

81.3 KB Created: 2021-08-17 14:35:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 494429e64dfdc56e94592d9aeccc1328 SHA-1: 9d58c0302e0c328ba723b891fe13d023428536a5 SHA-256: b3cbe26c5655b6bd2192a646b1d86db9244095acbc8589d5e2b6468308f12323
164 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://abril.pe/wp-content/plugins/super-forms/uploads/php/files/js76hverql8pnfuuqhfhaeg7c3/61347774713.pdf In PDF document text
    • http://kotolantopeni.cz/file/96072351790.pdfIn PDF document text
    • https://brandonsmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/2vdi2aagbs8s7vb4pg97ajg0a0/698761533.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608572ad1bf5d---95583349726.pdfIn PDF document text
    • https://cezartravel.hu/userfiles/file/nususizexamigegimekisu.pdfIn PDF document text
    • http://lamexmarket.com/uploads/files/lozoxavuzudarabusudeda.pdfIn PDF document text
    • http://tpdw.pl/userfiles/file/xuzilarul.pdfIn PDF document text
    • http://sazjah.com/wp-content/plugins/formcraft/file-upload/server/content/files/160891236d16ed---zelebadenusoziwe.pdfIn PDF document text
    • https://southwestlooms.com/admin/userfiles/files/wirojobibegat.pdfIn PDF document text
    • https://gamletaarnhuset.no/wp-content/plugins/formcraft/file-upload/server/content/files/16095e9b05ad29---14279854230.pdfIn PDF document text
    • https://educationindiajournal.org/ckfinder/userfiles/files/70964465881.pdfIn PDF document text
    • http://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/8498ab0e67946bddc454a0466b305dd6/sukafenodigusu.pdfIn PDF document text
    • https://gadd-asso.org/userfiles/file/muvevumalugasexojusominut.pdfIn PDF document text
    • http://okna-dvere-online.cz/media/upload/upload/file/18660433977.pdfIn PDF document text
    • https://eledigitalpr.it/allegati/file/43392889122.pdfIn PDF document text
    • http://czechdidgeridoo.com/admin/upload/file/39537105707.pdfIn PDF document text
    • https://treasurehunterdetectors.com/ckfinder/userfiles/files/fogipekajelutizobipugoxa.pdfIn PDF document text
    • http://www.advokat.com/app/webroot/img/fck/file/66075224333.pdfIn PDF document text
    • https://bk.knu.ac.kr/ckfinder/userfiles/files/63265191744.pdfIn PDF document text
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/160805cba4cc45---duwosejupav.pdfIn PDF document text
    • https://bdaudit.ro/userfiles/file/zugipewakixenufuranew.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071aebb145d6---dimodometitobefotisopek.pdfIn PDF document text
    • http://jdjcnc.com/upfolder/e/files/20210707004248.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082e1d5a3b27---83692207395.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=principles+of+accounting+i+com+part+1+text+book+pdfPDF link annotation
    • http://e1pl2.nazwa.pl/busy/fotki/file/93535210739.pdfIn PDF document text
    • 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_off0000d522.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD522 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ed39.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED39 11448 bytes
SHA-256: 5c0d7b223b97bba86e1a45565ded560c66eafb1034717475148455db8d9aeb17
font_02_sfnt_off000107e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107E6 17436 bytes
SHA-256: f04e34508d2bfc6a95d3b23e2ecfff54e0ff0c5dac29a424acaaa4fd8a6b5c86