Malicious PDF — malware analysis report

Static analysis result for SHA-256 837214a1b866eb6f…

MALICIOUS

PDF

88.0 KB Created: 2021-06-29 12:07:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 65c5c607b424e0ccd025e9ab7086cf6c SHA-1: cbb5af281b93e88084a7cada95fdd626b7f987eb SHA-256: 837214a1b866eb6fb6319fea14c6f2962dfb98709e629c5a7a3435d7425a47d9
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains numerous links pointing to compromised CMS upload storage and disposable hosting, suggesting a link farm designed to redirect users. The primary attack pattern appears to be leveraging these links for phishing or to serve a secondary payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://gptools.net/userfiles/file/53193578832.pdf In PDF document text
    • https://maxim-catering.de/wp-content/plugins/super-forms/uploads/php/files/2l00bvv4ndp4djus4a02c0j1p7/59773834502.pdfIn PDF document text
    • http://schs1968.com/clients/861610/File/milafa.pdfIn PDF document text
    • http://worthingtonpark101.com/userimages/37825419572.pdfIn PDF document text
    • https://www.thecandystoresudbury.com/wp-content/plugins/super-forms/uploads/php/files/2jceaeu4nvegask4doonohvlqr/49723388443.pdfIn PDF document text
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/b4ndf82tqq8dpdkouv7sdnskg9/73863994713.pdfIn PDF document text
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1606f65cc148f8---pexodajilonisolizax.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16088610fc0c86---46997229558.pdfIn PDF document text
    • https://ludifrance.fr/userfiles/file/58996038076.pdfIn PDF document text
    • http://galgalesh.com/userfiles/file/18253128544.pdfIn PDF document text
    • https://www.cukoyem.com.tr/wp-content/plugins/super-forms/uploads/php/files/rei4f8smg12n0k77rhi43mdpd3/gabefo.pdfIn PDF document text
    • http://www.sevenchurchestour.net/seven/wp-content/plugins/formcraft/file-upload/server/content/files/16080791acd6e7---bamopugoxakuboge.pdfIn PDF document text
    • https://3dreamvr.com/wp-content/plugins/super-forms/uploads/php/files/fbfe20b2dea9f93073d294f8af5ffe8d/mibaserufijuxela.pdfIn PDF document text
    • https://transcendenceit.com/wp-content/plugins/super-forms/uploads/php/files/7243d5cbb198ad31c1483ce649b4112c/47486217483.pdfIn PDF document text
    • http://phuclocvienjsc.com/uploads/image/files/83341285196.pdfIn PDF document text
    • http://shmountaineering.co.uk/wp-content/plugins/super-forms/uploads/php/files/0siivr7k2nko3lbutrvih6des4/68320757024.pdfIn PDF document text
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc5c8f3202---xokomifakuru.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/r182fijft1qsfd38s72eh3eaub/waxoxanutovorojupidemup.pdfIn PDF document text
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a85051d7a62---toxedezulezesinur.pdfIn PDF document text
    • https://www.blackandwhite-salon.com/wp-content/plugins/super-forms/uploads/php/files/eef4aa4e8a5190f35a9ae2e193fdc912/xagazorosejonajexilevedo.pdfIn PDF document text
    • https://www.sahabatkeluargahomecare.com/wp-content/plugins/formcraft/file-upload/server/content/files/160818e48b30ae---pasawew.pdfIn PDF document text
    • https://eyetracking.pl/userfiles/file/kewudubumegopa.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085eb1cd9763---13631082559.pdfIn PDF document text
    • https://g3az.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082ffbccea2d---19729546660.pdfIn PDF document text
    • https://www.bocamvigliesrooms.com/wp-content/plugins/super-forms/uploads/php/files/044dfd8053c09d43f0a0d36903764345/9133090273.pdfIn PDF document text
    • http://www.evisiontiendaonline.com/ckfinder/userfiles/files/91370697711.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=kwh+to+unit+of+electricityPDF 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_off0000f537.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF537 17480 bytes
SHA-256: 6b64a43c86ae3ec9c81adf791c95ff01a4215b5bf7f429564110808148b2e026
font_01_sfnt_off00012309.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12309 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013b20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B20 10396 bytes
SHA-256: d31ff7d5b20dad96a2e258628161079ccca0035f845eeecbd530fbb8a6caea19