Malicious PDF — malware analysis report

Static analysis result for SHA-256 b66fed37927fd365…

MALICIOUS

PDF

87.5 KB Created: 2021-08-14 17:44:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: f88a65d586fdfec1ed4d09739bea038e SHA-1: c9cf8c400f20b802c2f5db97140cc00bac9c3c2a SHA-256: b66fed37927fd3657dd49e3c3b3757f63453f47836214298878e79ec9c18a918
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The file functions as a link farm, containing numerous URLs that point to potentially compromised WordPress sites. These links likely serve to redirect users to phishing pages or download further malicious payloads. The presence of external URIs and link farm heuristics strongly suggests a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://wastran.ru/uplcv?utm_term=a+modern+approach+to+probability+theory+pdf PDF link annotation
    • https://winston-woodward.com/wp-content/plugins/super-forms/uploads/php/files/15f540a81e5a36d6c87af1a57bf4b69e/46285396833.pdfIn PDF document text
    • https://markeishahall.com/wp-content/plugins/super-forms/uploads/php/files/df5a989b6feb3889f1b3e321a174971d/50668082457.pdfIn PDF document text
    • http://www.petersmetalstitching.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607541862aad8---fixawejasaxeg.pdfIn PDF document text
    • https://www.prestigeautobody.com.au/wp-content/plugins/super-forms/uploads/php/files/b57537a9fa9cd65c7d350ac3f95e5a06/sudozelun.pdfIn PDF document text
    • https://leunamgroup.com/wp-content/plugins/super-forms/uploads/php/files/7ae0334fc34de94f96ae177a5ed3a5de/kiwotinipunakunaz.pdfIn PDF document text
    • http://studiomilano.eu/userfiles/files/sokazuluv.pdfIn PDF document text
    • http://christembassydocklands.org/wp-content/plugins/super-forms/uploads/php/files/4cc2bc833b17f1ca98caa40f943f585b/movulibarax.pdfIn PDF document text
    • http://www.highlandmetals.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16075f701df6b5---46282995619.pdfIn PDF document text
    • http://goreskyreunion.com/clients/b/ba/ba087d28c24afe6c5bc45fa062332e47/File/vudowoxasa.pdfIn PDF document text
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2db6d9858b---tosasu.pdfIn PDF document text
    • https://burgas-remonti.com/userfiles/file/nobaxusuzepesisoluxuxuw.pdfIn PDF document text
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/c41a7e018a79c2102cc47ae8fab85692/77409252466.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608d6729d3cfe---pidonatifala.pdfIn PDF document text
    • http://skrabl.pl/www/rpbd/fck/file/85109012380.pdfIn PDF document text
    • https://fokusmedia.com/images/uploads/wanex.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160971433dde7f---fudeduvusefi.pdfIn PDF document text
    • http://sungsam.net/userData/board/file/28837520993.pdfIn PDF document text
    • https://prawobrzeze.info/userfiles/file/xojesakurojaxivefexepuje.pdfIn PDF document text
    • https://www.beachesbrewing.com/wp-content/plugins/super-forms/uploads/php/files/e2e30b7d9032b2ae2a9606e746c90263/matufazabugod.pdfIn PDF document text
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/98qfk0oks5c063ictgvgql2ror/gukiwix.pdfIn PDF document text
    • http://hifitness.hu/userfiles/file/34088881940.pdfIn PDF document text
    • https://skazkavdom.com/wp-content/plugins/super-forms/uploads/php/files/4af6530bf6fbae18fd73fe4cac1c708f/22261629533.pdfIn PDF document text
    • http://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609cb33e3a15e---69776720590.pdfIn PDF document text
    • http://kingspec.su/wp-content/plugins/super-forms/uploads/php/files/n3v28dvc660dfa8d5n4fk6c6ge/79468374831.pdfIn 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://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_off0000f4b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4B3 10952 bytes
SHA-256: 6140430352aca6ded2ce9721355c83a7d9f6162a51af3ef4fe96c637309f1c61
font_01_sfnt_off00010d9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D9E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000125b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125B0 16416 bytes
SHA-256: 23b1566787c8b0ee5bcc9c5f4193aec0cff8239fc04288be4525175bda1e7c8d