Malicious PDF — malware analysis report

Static analysis result for SHA-256 d1cba50d2168fba7…

MALICIOUS

PDF

73.0 KB Created: 2021-09-05 18:01:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: d71473d9aefa5037f4ddacd2225ce6cf SHA-1: e33ae6cd0ddf391d8b8eafae40d127174919333c SHA-256: d1cba50d2168fba7cff97ef88159772b7a9fae22bce2a6db5e66c5fad0e4396b
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm. The ML classifier strongly flagged this PDF as malicious, and the heuristics suggest it's designed to redirect users to external sites. No scripts were extracted, but the primary attack pattern is the distribution of malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://rh-h1tapi-turbo.com/contents//files/71968129808.pdf In PDF document text
    • https://www.perfumista.co.uk/wp-content/plugins/super-forms/uploads/php/files/e4329afea09160d588e7ee83ee1581e7/33337054201.pdfIn PDF document text
    • https://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/1607d949794336---gatexanu.pdfIn PDF document text
    • http://chiengthai.com/file_media/file_image/file/julofi.pdfIn PDF document text
    • http://lyzebrno.cz/userfiles/file/xoxuwekubarunagukati.pdfIn PDF document text
    • https://stdtekstil.com/upload/ckfinder/files/44961345335.pdfIn PDF document text
    • http://divorce-difficile.fr/userfiles/file/latarinorojixipawabisalep.pdfIn PDF document text
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/160c366302826b---wenikaxokarupujotusudu.pdfIn PDF document text
    • https://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/j84v2hltnpoqqftkt5mcuej8fd/69441745136.pdfIn PDF document text
    • http://mesterek.net/tmp/52075890235.pdfIn PDF document text
    • https://nocenzura.space/web/img/podborky/files/notifafe.pdfIn PDF document text
    • http://dream-mebel.com/pic/file/viritubok.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8bffce72dc---zokew.pdfIn PDF document text
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d020e00651---nanurusewodonebalokig.pdfIn PDF document text
    • https://prosperitas.be/data/assets/file/12103423347.pdfIn PDF document text
    • http://gpe-el.pro/ckfinder/userfiles/files/50013502575.pdfIn PDF document text
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f015d2667b8---30252103840.pdfIn PDF document text
    • https://bilegt.mn/userfiles/files/wigoxopimuwafekofezajax.pdfIn PDF document text
    • http://pnmanagementsolutions.in/uploads/laberemo.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609c978a3f238---tekoxufiwawaxezirebarit.pdfIn PDF document text
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/88b30de1e46ea6f423927d3def5565e5/96325245654.pdfIn PDF document text
    • https://wasael.com/userfiles/file/18775981056.pdfIn PDF document text
    • https://inchiriereelicopterromania.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160848f85d31cf---98568366330.pdfIn PDF document text
    • https://digireg.nz/upload/40890333282.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=hr+consulting+company+profile+pdfPDF 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_off0000be52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE52 15220 bytes
SHA-256: 71fd16102453b573ccd7b69ccfc00fda4f382da41f54f767b446c00873d14343
font_01_sfnt_off0000e491.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE491 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fca8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCA8 11168 bytes
SHA-256: a41f0bf957330ef886b394debf93d1e5643e09bf4ffa95bddd7bd94379bc8a0e