Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8f1b2770856ce3d…

MALICIOUS

PDF

82.6 KB Created: 2021-09-08 09:25:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: a7e916abbfd9cd7200874d6c80a6ad49 SHA-1: 4f1ff757bb654e200d38b5bc4ab192644065691c SHA-256: d8f1b2770856ce3dcd8a5a2110abbb7977f571b90e94f4440373a57fcd7b17ce
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous links pointing to compromised websites and disposable hosting, suggesting an attempt to distribute further malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using such links for SEO manipulation or to host malicious files. The ML classifier strongly flagged this PDF as malicious, supporting the conclusion that it is part of a malicious distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 6

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/4f0d2fb11392d028c090bcc67052a507/54702462344.pdf In PDF document text
    • https://machnhaduong.com/images/uploads/files/43473228483.pdfIn PDF document text
    • https://connect.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/b91e4e354bc31ed97e37a1af3104c632/77419368024.pdfIn PDF document text
    • http://ingfrimale.com/userfiles/files/95673305341.pdfIn PDF document text
    • http://staropolski.net/Upload/file/74407075686.pdfIn PDF document text
    • http://www.thebetterinsurance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160889dbc5cac0---gubowerukufako.pdfIn PDF document text
    • https://wfbulgaria.com/uploads/wysiwyg/files/33271581244.pdfIn PDF document text
    • http://www.alrafeef.com/faisaliya/js/ckfinder/userfiles/files/punederegaruvapokitesumib.pdfIn PDF document text
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/93c44241e0aa05b06d0e309aec20f428/85785586753.pdfIn PDF document text
    • http://skolky.info/foto/images/file/66819770968.pdfIn PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160f9d6a7bc5c1---84704440624.pdfIn PDF document text
    • http://acm-medicali.it/userfiles/files/43965042730.pdfIn PDF document text
    • https://rcot.org/userfiles/file/luralewegaponubigujegogis.pdfIn PDF document text
    • http://dtjxbpzx.com/filespath/files/20210907095613.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/16072994141cc6---42171353276.pdfIn PDF document text
    • https://takipcisec.com/calisma2/files/uploads/36698730300.pdfIn PDF document text
    • http://www.ferm-matic.fr/upload/file/xijajiw.pdfIn PDF document text
    • https://www.emma-solutions.de/wp-content/plugins/formcraft/file-upload/server/content/files/160810b9fbc4fc---57803573532.pdfIn PDF document text
    • http://valaptop.com/ImagesVA/file/mowalomege.pdfIn PDF document text
    • https://abofahed.com/userfiles/file/zopineretanelaxa.pdfIn PDF document text
    • http://drsuthichai.com/userfiles/files/6600827004.pdfIn PDF document text
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/8b68bbfc450603f5aac1afd45ef789fc/keserivusodarupinulezuvir.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=purchasing+and+supply+chain+management+5th+edition+pdf+free+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_off0000de94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE94 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f6a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6A6 16772 bytes
SHA-256: 1fb9875e67bd7a2a42bac2e08c97f75f867e22f05a4b6c6c52b5dc6b404f0aed
font_02_sfnt_off00012193.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12193 11500 bytes
SHA-256: 8a0192a8d5b9ab5ea45641c74ae09babdc245d98982d2a51c0c142075ff2df75