Malicious PDF — malware analysis report

Static analysis result for SHA-256 d97ca989509afc23…

MALICIOUS

PDF

77.9 KB Created: 2021-06-11 06:16:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: f15389b92dc4f1739c033534aec6b165 SHA-1: ed36392c8d842e677bfc70a3cd4611d8dd5bfbc1 SHA-256: d97ca989509afc233aa86e22ce5bcdf17462e22458f1643744c116816ec71d8f
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of embedded URLs pointing to various compromised websites, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, and heuristics identified it as a link farm on disposable hosting and pointing to compromised CMS uploads. No scripts were extracted, but the primary attack pattern is the distribution of malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 https://pistant.ru/uplcv?utm_term=kane+and+abel+book+review PDF link annotation
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098898cf2f48---45349138.pdfIn PDF document text
    • https://csom.cz/wp-content/plugins/super-forms/uploads/php/files/34e668547c664482e66c511a11927567/68662873699.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/16082029bc63fb---memaboxijupenolanoso.pdfIn PDF document text
    • https://lsp.od.ua/wp-content/plugins/super-forms/uploads/php/files/bjl0ahuehu362uuvsjiene5u87/8302801172.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/9eb7daf7083981a962f5306fc0a4ce80/8079484593.pdfIn PDF document text
    • https://cmsschoolkg.org/userfiles/file/44923532732.pdfIn PDF document text
    • https://fundreamz.com/ckfinder/userfiles/files/luxax.pdfIn PDF document text
    • https://ifacemount.com/wp-content/plugins/super-forms/uploads/php/files/n63t3pmbctfmfg7fdqg4llnn4k/nikekesanimilagikawubaj.pdfIn PDF document text
    • https://centar-znr-zop.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1607243d4aab79---mokolokumaxu.pdfIn PDF document text
    • https://walkandsmile.com/userfiles/file/70731725576.pdfIn PDF document text
    • https://cwlighting.com/wp-content/plugins/super-forms/uploads/php/files/43e0a28359f2489ad5b6fab8781428d1/zaperudezimujok.pdfIn PDF document text
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/1afe626c2914a7bb1f030e75fa59932d/42114829813.pdfIn PDF document text
    • https://rescue.bg/wp-content/plugins/formcraft/file-upload/server/content/files/160acd152a246e---2820088699.pdfIn PDF document text
    • http://grupomarsamo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160747688cf0a6---40420587298.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f253.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF253 4968 bytes
SHA-256: 2653a67dad43dcded16f7223d1d277c4d89907adcc085f6d74dad74db60bd2e5
font_01_sfnt_off0001035c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1035C 11168 bytes
SHA-256: 8a91969855c8c7cade64cf3bf8a8bf3cacc826464c7167c7e429ac07bad433b9