Malicious PDF — malware analysis report

Static analysis result for SHA-256 91f944b793190303…

MALICIOUS

PDF

105.6 KB Created: 2021-06-27 17:03:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: cab594f69dbd609fcf1e4618ad43e5b8 SHA-1: 8bcf6501e7e10757f0fae38796b12e6dbbd07ad9 SHA-256: 91f944b7931903036d98e876969b2e6f5c0e895740ff5f28d76de7335893ee6c
156 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 WordPress sites utilizing the Formcraft plugin for file uploads. The ML classifier and ClamAV detection strongly indicate malicious intent. The primary function appears to be acting as a link farm, directing users to potentially malicious content on these compromised hosts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9790

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 http://multiseal.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/160b792ad89339---livakaxulewuwumakepij.pdf In PDF document text
    • https://paperland.bg/uploads/file/73749414003.pdfIn PDF document text
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/160bc6f9aed210---laxexapewogilel.pdfIn PDF document text
    • https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082a0af1c29a---venunaruron.pdfIn PDF document text
    • http://www.rebranded.tv/wp-content/plugins/formcraft/file-upload/server/content/files/1609cc3cf1e148---52491996226.pdfIn PDF document text
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/9f0t3ti3vdvbk354dmlutaqs73/lomexijede.pdfIn PDF document text
    • http://volamtuyetthe.com/userfiles/file/mirefagavulapelotafaz.pdfIn PDF document text
    • http://www.socalgreatwhite.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a772fe6b0f---64268372552.pdfIn PDF document text
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160ac47cca7ece---93716855135.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/09f1a4f7f86321ab9378621fe8ef7ce9/biwewiliraket.pdfIn PDF document text
    • http://kayamedbursa.com/userfiles/file/62846571574.pdfIn PDF document text
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/160afc6afb10c0---nevoseto.pdfIn PDF document text
    • http://change4best.ru/upload/file/69127739511.pdfIn PDF document text
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084988bad155---79804944683.pdfIn PDF document text
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/da16845e3addb1056aba19d2a4744599/87570600097.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b2c5fd76aee---mikuvivetamuj.pdfIn PDF document text
    • http://www.danvillern.com/wp-content/plugins/super-forms/uploads/php/files/8138mh0rjuru192l2oi262nlv6/30468980801.pdfIn PDF document text
    • https://www.charroninc.com/wp-content/plugins/super-forms/uploads/php/files/8cc475e6f0e39a55f702be823645d857/32074449700.pdfIn PDF document text
    • https://harpethvalleypto.org/wp-content/plugins/super-forms/uploads/php/files/bbca3ec1c7963b72f662611f733b4ae1/levekudimopibawavojakuluj.pdfIn PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160d77fcf97129---wejizigo.pdfIn PDF document text
    • https://xn----9sbccjdbca7cyaieg1a3j.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/b2b53f294c07c0212d36cff9a30d4d99/fazerewavilu.pdfIn PDF document text
    • http://mdsalon.ru/img/lib/file/jupawovuvexodolezop.pdfIn PDF document text
    • http://ahxxzx.com/userfiles/202104/file/modafasavidakozifebaw.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/160a02eb187c94---dumabapel.pdfIn PDF document text
    • http://placc.info/up_image/pozanutiburetugaf.pdfIn PDF document text
    • https://atlanthealth.com/wp-content/plugins/super-forms/uploads/php/files/20a1cbb7fe2565a6ffbba2b7f5a80d46/lapetegemovobalamos.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=avery+dennison+6404+manualPDF 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_off0001389f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1389F 17800 bytes
SHA-256: 065de6c3d9cb8fd4a6f388e0c9fdf7c7ef7bee7a75bd42ba71659984c959187d
font_01_sfnt_off0001679c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1679C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00017fb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17FB3 10940 bytes
SHA-256: 7140e60dca0112dc070bd1a1be0c2e5ad2e67406630150877ed6025a245de468