Malicious PDF — malware analysis report

Static analysis result for SHA-256 51d1ee4c0e112467…

MALICIOUS

PDF

86.8 KB Created: 2021-06-28 04:24:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 41bd58fdebec4b03779488cba3be1f0b SHA-1: ec17ab12dda21db48c77626c64d74df3df7c0cb4 SHA-256: 51d1ee4c0e1124676d15e4c8893d310f945df7e8e6bf313a33f6cc47b4414819
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised WordPress sites and other disposable hosting, suggesting it functions as a link farm designed to redirect users to malicious content. The presence of embedded URLs and the nature of the links strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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 https://crysiq.ru/uplcv?utm_term=repetitive+transcranial+magnetic+stimulation
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/57140aaa7ded8e9681b926db50631cea/sijiwalatokeroxexomi.pdf
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160aba9e8614f7---88317004265.pdf
    • https://apoiotelecom.com/imagens/img_fckeditor/file/sivivodeluv.pdf
    • http://rowanfamilyreunion.com/clients/28915/File/sixoxuvudenenakunexite.pdf
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bb890f6362a---mazikofanepa.pdf
    • http://blueyee.com/upload/file/311118241870.pdf
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/ad80f11edc540d00f824d8950aaa02ff/degepikokinanomogudinare.pdf
    • https://amalighting.com/wp-content/plugins/super-forms/uploads/php/files/fec6aa961425e3cde344ff0958165432/24628560500.pdf
    • http://bookblog.kr/data/file//files/14319140501.pdf
    • http://adamlegal.com/userfiles/file/1950843439.pdf
    • https://propbrains.com/wp-content/plugins/super-forms/uploads/php/files/bvd8hqnaim1qd5eos0mf0u8uh6/kufagokizad.pdf
    • http://www.bash.cl/media/file/81212773682.pdf
    • https://www.accidentinjuryalbuquerque.com/wp-content/plugins/super-forms/uploads/php/files/klgc2j4rkmroe729k64jn5f5nv/24717776393.pdf
    • https://www.lightingsolutionsinc.net/wp-content/plugins/super-forms/uploads/php/files/79790b449528bcbb1fb801af467129ab/mamifiwogitexowonitizajuz.pdf
    • http://spoanalyze.com/wp-content/plugins/super-forms/uploads/php/files/2aabb0b0937652f527308e38944ae9b1/gipuvanojarobepogamotuja.pdf
    • https://dazzlin.co.uk/wp-content/plugins/super-forms/uploads/php/files/c903a7e18f642724ed5df56ba71dd8d4/18545941306.pdf
    • http://akvari-um.ru/userfiles/file/7500367059.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085403eb80de---fopepexosuvisiritumivir.pdf
    • https://groupunsur1.com/contents//files/sefezepapulabezabukoki.pdf
    • http://gorisum.net/fckeditor/upload_file/file/tibolawepivetameju.pdf
    • https://lasvegasrebath.com/wp-content/plugins/super-forms/uploads/php/files/801a5269e2ae6384e8078604645a3891/nowam.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_off0000eb3d.bin
5bb01f5b99ae95f224632a14fe2fcb61a437458eb17ced8dc6d1121ca77e319f
pdf-font-stream PDF embedded font (sfnt) at offset 0xEB3D 10928 bytes
font_01_sfnt_off00010493.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10493 16792 bytes
font_02_sfnt_off00011ca5.bin
31b174cadbb2b54be38b5a629d366f4665304280d464635b38e26f59a215eb63
pdf-font-stream PDF embedded font (sfnt) at offset 0x11CA5 18544 bytes