Malicious PDF — malware analysis report

Static analysis result for SHA-256 c173113ac945616c…

MALICIOUS

PDF

75.1 KB Created: 2021-09-05 19:08:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-02
MD5: eccb26113af88dc2528561a168b238ee SHA-1: f6985ae48da5c5e9cc6bf61812de435c77afae9e SHA-256: c173113ac945616c4982ab7020e78d5003a127b4bc222b18698315ca85a2b00b
96 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by 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. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://n2nlah.org/UserFiles/file/27318735207.pdf In PDF document text
    • https://ocvirapuato.com.mx/wp-content/plugins/super-forms/uploads/php/files/cedce886dfc0b1844bba6af425d1ea35/70405064797.pdfIn PDF document text
    • http://njxinbell.com/upload/files/puvurizaxu.pdfIn PDF document text
    • http://www.bufolari.com/public/immagini/file/49730947764.pdfIn PDF document text
    • https://www.harnoordesigns.com/wp-content/plugins/super-forms/uploads/php/files/39vtqjhkg1c2ilkn0i2f9vfhl7/82874392211.pdfIn PDF document text
    • http://ellerbeefamilyreunion.com/clients/874543/File/sojila.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d06ea39a77---18156339136.pdfIn PDF document text
    • http://vishwkarmaenterprises.com/webroot/img/userfiles/files/gajomitemixetibaporo.pdfIn PDF document text
    • https://letajicikoberce.cz/userfiles/file/67629000232.pdfIn PDF document text
    • http://myshiou.com/uploads/files/202108152148387434.pdfIn PDF document text
    • http://zubrcup.by/files/files/81641703797.pdfIn PDF document text
    • https://propage.q-cloud.net/upload/ckeditor/pages/files/pirokilobagofeseriwudorid.pdfIn PDF document text
    • https://www.ideaklinik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160777c86f21db---93606978735.pdfIn PDF document text
    • https://cleartunemonitors.com/ckfinder/userfiles/files/95116043356.pdfIn PDF document text
    • https://jollytime.ru/wp-content/plugins/super-forms/uploads/php/files/98ac50f9de3762f677140d871c00d122/nenemidomejanedolomore.pdfIn PDF document text
    • https://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b99340e8341---resutewigugukexipibogil.pdfIn PDF document text
    • https://www.kngroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609834f39fcef---25700026074.pdfIn PDF document text
    • http://laiyi-art.com/userfiles/file/52674230334.pdfIn PDF document text
    • http://fteq.ru/files/file/jufoxaxebibuta.pdfIn PDF document text
    • https://matras-matrasych96.ru/admin/ckfinder/userfiles/files/87052777197.pdfIn PDF document text
    • https://www.llgnjinc.com/wp-content/plugins/super-forms/uploads/php/files/99cea4534b5eb2a91b80e21881bd20b0/figisekedinevidudat.pdfIn PDF document text
    • https://susta.vn/userfiles/file/tofevuvamedewabotuparuz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=rrb+group+d+syllabus+telugu+pdf+downloadPDF 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_off0000c1cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1CC 16996 bytes
SHA-256: a094111a11400c21f050b879c4ae3ecd7994aee6a5d7bf985b1e70be4ed54072
font_01_sfnt_off0000ed62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED62 11064 bytes
SHA-256: a98875f2f6e2ac07339e4fbad9ce80e1001acafed110b4e48a7a2ea13ac54813
font_02_sfnt_off000106fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106FE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1