Malicious PDF — malware analysis report

Static analysis result for SHA-256 f6c143a6a5d14f51…

MALICIOUS

PDF

82.6 KB Created: 2021-09-04 20:37:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 453bb8656f1fceeaafcabe2747520630 SHA-1: b9c44d52af2ddd4f7e83191c8b350f8d5c6b14f3 SHA-256: f6c143a6a5d14f5123271f55b7bc3c2ddfab441829736f531ed2d82513563b0a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of links, many of which point to compromised CMS upload directories. This suggests the document is designed to act as a link farm, potentially leading users to phishing sites or malware downloads. The ClamAV detection and ML classifier further support its malicious nature. No scripts were extracted, but the structure and URL patterns are indicative of a phishing or content-luring attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://nusamulticentralestari.com/Uploads/userfiles/files/polijusatagex.pdf In PDF document text
    • http://2990592.ru/ckfinder/userfiles/files/monubezimikorugij.pdfIn PDF document text
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/b31fc4872db72f384f7dcaaaa6898545/16463984137.pdfIn PDF document text
    • http://intertexmedical.com/userfiles/files/wuzujazedot.pdfIn PDF document text
    • http://lateonsettay-sachs.org/userfiles/file/74896704811.pdfIn PDF document text
    • https://phase1acoustics.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ca2eb86eade---68493922942.pdfIn PDF document text
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/160777e273dbd0---53935526264.pdfIn PDF document text
    • http://westboroughhigh76.com/clients/b/bc/bc4984db1d461a603911d7e4814e3e59/File/zabexigusitije.pdfIn PDF document text
    • http://www.caslyn.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160b5639d0fb20---18808931780.pdfIn PDF document text
    • https://nnt52.ru/userfiles/file/16648899950.pdfIn PDF document text
    • http://aldwalia.com/userfiles/files/tivufumogaj.pdfIn PDF document text
    • http://santehnika34.ru/images/file/nexukalujolomiwu.pdfIn PDF document text
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/1607b0343a4d10---gemanorefakifurojus.pdfIn PDF document text
    • https://red-adlay.com/upload/files/gumage.pdfIn PDF document text
    • https://washlounge.in/ckfinder/userfiles/files/94683639173.pdfIn PDF document text
    • http://becucci.it/userfiles/files/12474011891.pdfIn PDF document text
    • http://joyear.com/ckfinder/userfiles/files/80385036367.pdfIn PDF document text
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/r8i9k5hnq6pd3gsqrs0c3atead/nukom.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1608b63367bead---kivesonixojodegovoguzovo.pdfIn PDF document text
    • http://thefutureofgolf.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160907c6fcc0c6---86387962480.pdfIn PDF document text
    • http://erbilsunhotel.com/wp-content/plugins/super-forms/uploads/php/files/k0vdc5hnsvrjrki04g5n8h27c1/fosevapow.pdfIn PDF document text
    • https://hanahana.vn/media/ftp/file/lapofolatakebajutuw.pdfIn PDF document text
    • http://gf-location.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16079a657bf261---86161729069.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/1607dd3a00925d---vinixasoladakali.pdfIn PDF document text
    • http://alsumiri.net/wp-content/plugins/super-forms/uploads/php/files/b2dc5e14622c434254ae61d824a6139a/wodawaroloj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=ransomes+crawler+manualPDF 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_off0000dd9c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD9C 18496 bytes
SHA-256: 11dc6320ad22af783d681759c6396b937e12e07353978e8ad8dc5eb57f0fe8d0
font_01_sfnt_off00010d7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D7D 10432 bytes
SHA-256: f348b88bd4e3f83b1c21ba4333af3732716d016d039ae2614bb5393a49217441
font_02_sfnt_off0001253a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1253A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1