Malicious PDF — malware analysis report

Static analysis result for SHA-256 251862a0d6ac8ff8…

MALICIOUS

PDF

70.5 KB Created: 2021-10-05 05:56:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: ccd7855a659e105877af1eac1f18e3bd SHA-1: 2bd48ef894f592e2f7215d815079903882f05379 SHA-256: 251862a0d6ac8ff8eaaf17d0471fb7607f7482070f26d65f8ef01c2934bbd58f
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external PDF files, many hosted on domains flagged as link farms or potentially compromised CMS uploads. The ML classifier strongly indicated maliciousness. While no scripts were explicitly extracted, the structure and URL patterns suggest a malicious intent to lure users to other malicious documents or potentially exploit-hosting sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 5

  • 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://klinok-saintp.ru/files/dipekegajajulabipi.pdf In PDF document text
    • http://ger.versa.ru/documents/files/10532875817.pdfIn PDF document text
    • https://villatoscana-pi.it/userfiles/file/vixizazonozubimi.pdfIn PDF document text
    • https://bilbox.es/wp-content/plugins/super-forms/uploads/php/files/e7b7848bdcc19dd2bbbe63f3a8dcd6fa/fawepif.pdfIn PDF document text
    • http://www.electricman.in/demo/frontend/web/uploads/files/felowanizixomimipu.pdfIn PDF document text
    • https://searches.onlineconvey.com/userfiles/file/98079362353.pdfIn PDF document text
    • http://modernplating.com/userfiles/file/zupalaxipasusapedigokugal.pdfIn PDF document text
    • http://www.moyekolodin.com/files/6168194765.pdfIn PDF document text
    • https://israelonthehouse.com/wp-content/plugins/formcraft/file-upload/server/content/files/161324a58ccd9f---nefavakowolakokipumi.pdfIn PDF document text
    • http://x04ydivan.ru/userfiles/file/56710007134.pdfIn PDF document text
    • https://pointswestliving.com/ckfinder/userfiles/files/87744763357.pdfIn PDF document text
    • https://tauthuy.vn/upload/files/88292557815.pdfIn PDF document text
    • https://ptogel1.com/contents/files/subupabiwimowuxedutijepu.pdfIn PDF document text
    • https://korzayithalat.com/spot/admin/fckeditor/userfiles/file/rowiripuvalikabunabibivar.pdfIn PDF document text
    • https://merlak.ru/userfiles/file/dakufefupizejosanarota.pdfIn PDF document text
    • http://vanguardhungary.hu/userfiles/file/sufinazon.pdfIn PDF document text
    • http://istanbulballoons.com/ckfinder/userfiles/files/77160794001.pdfIn PDF document text
    • https://www.mmgrowersg.com/ckfinder/userfiles/files/fisalu.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/1612ebbf21234c---250484002.pdfIn PDF document text
    • http://blessingsngo.in/userfiles/files/dolegurosu.pdfIn PDF document text
    • https://citytrafik.nu/images/file/77902851169.pdfIn PDF document text
    • http://www.giuseppe.ru/ckfinder/userfiles/files/tivuzelis.pdfIn PDF document text
    • http://mh-gartengestaltung.de/userfiles/file/xezosisuzojevepawuna.pdfIn PDF document text
    • http://rallyteamwalraven.nl/file/21964489548.pdfIn PDF document text
    • https://abctranslink.com/ckfinder/userfiles/files/pafigajudodudajunexilenaj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=what+is+lm+curve+in+macroeconomicsPDF 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_off0000b3d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3D8 10652 bytes
SHA-256: f2ce9f5cb8eea95c98089c0349bb3c8eb9137411bab721497b706ddee6fab085
font_01_sfnt_off0000cc16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC16 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e428.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE428 15660 bytes
SHA-256: 771099edade3e07103e2356473be06be100b77fffc0f1251d5bb143437259a4f