Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8c7e6e07f6e6a7b…

MALICIOUS

PDF

86.3 KB Created: 2021-08-19 23:54:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 01a78959e59e05181a90de622765a174 SHA-1: c922292bb62d63094418a793812f29db2d4ab995 SHA-256: d8c7e6e07f6e6a7b8046bcd3f0433da7d1dd1a781228017541146f8f262b0518
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF that exhibits characteristics of a phishing lure, specifically a fake invoice or payment check, as indicated by the 'SE_INVOICE_LURE' heuristic. It contains numerous embedded URLs pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The ML classifier strongly flagged this PDF as malicious, and ClamAV detected it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 7

  • 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.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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://ketchas.ru/uplcv?utm_term=how+to+check+my+ptcl+bill+paid+or+not
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/8c370389244fdce78a9c856917560526/63644914917.pdf
    • http://hoshitorionline.com/uploads/files/57752221998.pdf
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/1607a9bae73378---fidijojelopakusukojepa.pdf
    • https://elearning-chemistry.ro/userfiles/file/vegaza.pdf
    • http://originalcheck.it/public/img_admin/file///77197993534.pdf
    • https://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/262049256314be2324f1defcb7b1071b/46611152923.pdf
    • http://rethabise.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160c96f3934c15---64136093944.pdf
    • https://iescolumbus.org/wp-content/plugins/super-forms/uploads/php/files/20b75fb6660420309a699693ecac9778/88737857073.pdf
    • http://tysons-cafe.com/uploads/files/7542245048.pdf
    • http://jeremypourstarlight.com/clients/5/53/539822683240d2210db56c0084569a8b/File/67759603293.pdf
    • http://kemenyseprosiklos.hu/upload/file/dajewenelumobit.pdf
    • https://salvatoredivilio.it/userfiles/file/vizusopegagizuv.pdf
    • http://shinserviceodi.ru/wp-content/plugins/super-forms/uploads/php/files/eaf1bad6c8ce46e5cd8b23157975354c/90261784852.pdf
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/ia8jomqld0c7l9e0svdfe0g7ld/52007607448.pdf
    • http://yuha.be/_files/file/kiboxejekegaparikoregev.pdf
    • https://ckmusicdesign.nl/userfiles/file/56772081013.pdf
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/160fc6d844f658---wogugamagewopox.pdf
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160c8a6e25ef98---74500616075.pdf
    • http://ahdongjiu.com/upload_fck/file/2021-6-29/20210629110624120297.pdf
    • https://bykevin.com/wp-content/plugins/super-forms/uploads/php/files/8fb525c3bba664820a89abff9244474c/25469120202.pdf
    • http://www.fred-robin.com/ckfinder/userfiles/files/36607039216.pdf
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9bbf57014a---548953843.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ec6f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC6F 16792 bytes
font_01_sfnt_off00010486.bin
446b949acb863e6e5b71812f1a814e1337a0647e08527e1872051f28b36ce9d4
pdf-font-stream PDF embedded font (sfnt) at offset 0x10486 11036 bytes
font_02_sfnt_off00011dbe.bin
908cb716cbac9f98020f6d97a411a9e10be12fbf36e310161c028e16e6251781
pdf-font-stream PDF embedded font (sfnt) at offset 0x11DBE 16768 bytes