Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1d546db3a541123…

MALICIOUS

PDF

84.6 KB Created: 2021-08-26 09:20:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 98529567d18707d302beeebcc3fac8b7 SHA-1: b11b658201eb344c09e9907ed4f661d02ce8e39e SHA-256: b1d546db3a5411233f577f52ae87e34e4390aebe69ee2a688024394a768ae46d
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous distinct hosts, many of which appear to be compromised WordPress sites. The ML classifier strongly flagged this PDF as malicious, and the heuristic firings indicate a pattern of linking to potentially malicious content. The primary goal appears to be directing users to external, untrusted resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://castel.ro/userfiles/file/benuzutogajebogiwemuvija.pdf In PDF document text
    • http://wowbond.com/upload/Fckeditor/file/safekixegeniremowobevep.pdfIn PDF document text
    • http://rlangkhan.com/upload/userfiles/files/mikolanefovuta.pdfIn PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/c9b06aee79bec69e066db060f71b02d1/55015054398.pdfIn PDF document text
    • https://msiutilities.net/documents/dovigudifimivijejiles.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a74b9c610dd---jogejakudexojozukoworabu.pdfIn PDF document text
    • https://lyna-garage.com/htdocs/cljr/data/files/80426512978.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1609a1e230beeb---99744196462.pdfIn PDF document text
    • https://www.pharmaright.ca/wp-content/plugins/super-forms/uploads/php/files/k5ft123493u2kdg9san1vjg02e/24127904699.pdfIn PDF document text
    • https://ehbo-oostkapelle.nl/userfiles/file/76146469704.pdfIn PDF document text
    • http://achilleferolla.it/userfiles/files/kenilolanuzekubusivije.pdfIn PDF document text
    • http://damnoen.com/ckfinder/pho/files/99341077760.pdfIn PDF document text
    • http://www.almansori-ye.com/almansorifiles/files/16313980568.pdfIn PDF document text
    • https://cursosgratuitosonline.es/wp-content/plugins/super-forms/uploads/php/files/dlijp8j3p5n9e1nfm4ejhcda29/57858069945.pdfIn PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/161268d806b160---63697503753.pdfIn PDF document text
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/cb1f5dba897cc884cc32eb15f7493430/4200925961.pdfIn PDF document text
    • http://iburgisidimarsala.eu/userfiles/files/lezawajagofebet.pdfIn PDF document text
    • http://ackerviewguesthouse.com/userfiles/file/savamevegesa.pdfIn PDF document text
    • http://www.kzhep.in.ua/wp-content/plugins/super-forms/uploads/php/files/mf6564s0fc6284oqqmfl813bg5/91573373674.pdfIn PDF document text
    • http://n2nlah.org/UserFiles/file/4069976929.pdfIn PDF document text
    • http://arniestribu.com/campannas/file/taxata.pdfIn PDF document text
    • https://flardochform.se/userfiles/file/526085187.pdfIn PDF document text
    • https://108pizza.pl/uploads/userfiles/files/72007209215.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb2156a5035---62718190272.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=might+not+give+up+a+boogie+lyricsPDF 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_off0000e32b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE32B 11068 bytes
SHA-256: 4667f829f3529d4eb88c873a6f2f2203c96f619f6a761f22f1d2b92addc605e2
font_01_sfnt_off0000fcba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCBA 17800 bytes
SHA-256: 86bc110220974dd18b152af633b602500e90fa675ea03a52d95dca87614fcda0
font_02_sfnt_off00012b31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B31 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1