Malicious PDF — malware analysis report

Static analysis result for SHA-256 5fea8c2257e7587e…

MALICIOUS

PDF

76.0 KB Created: 2021-09-16 15:48:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 30cd9b76d2458833cadc55af5ee69676 SHA-1: 98cc9a3f94a92ffd9a7551e71f5b8c449936831c SHA-256: 5fea8c2257e7587ebbc0b58e7d9f9526035c3f99233ac5c487cc5db1a3c059f3
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 WordPress sites. The ML classifier strongly flagged this PDF as malicious. The presence of link farms on potentially compromised hosting suggests an attempt to manipulate search engine results or distribute further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16135e5c74bd4c---97490917000.pdf In PDF document text
    • https://leciv.fr/uploads/FCK_files/file/fikimulixebafel.pdfIn PDF document text
    • http://vietsinphar.com/uploads/files/78718889878.pdfIn PDF document text
    • http://braintradingbcn.com/wp-content/plugins/super-forms/uploads/php/files/79aa6fa6a1f8c758691a52670128c7f6/lumosudinopig.pdfIn PDF document text
    • https://tucarrorentacar.co/ckfinder/userfiles/files/fadisapudupovigadake.pdfIn PDF document text
    • http://guidesdugrandlarge.fr/images/import/file/54937375902.pdfIn PDF document text
    • http://feldbach-tourismus.at/files/29415299832.pdfIn PDF document text
    • http://www.bash.cl/media/file/pepaluniwirubebokotalir.pdfIn PDF document text
    • https://nceptionsolutions.com/wp-content/plugins/super-forms/uploads/php/files/62668aab87f7e3b60e3eea13293e72be/71967434350.pdfIn PDF document text
    • https://floresdeserrezuela.com/aym_image/files/lisosedugevekizesoxij.pdfIn PDF document text
    • http://www.pilartangguh.com/file/zuzivibifefuxonosawetulo.pdfIn PDF document text
    • https://printsolutions.ro/uploads/wysiwyg/files/dovelurufenuwunif.pdfIn PDF document text
    • http://maiodi.com/userfiles/files/80755872392.pdfIn PDF document text
    • http://zgic.ru/!upload/files/569293862.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/46319752756.pdfIn PDF document text
    • http://votejoedestefano.com/editorData/file/89632046041.pdfIn PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612f42369a4c7---28076925234.pdfIn PDF document text
    • https://hunde-katzen.at/soubory/43999284386.pdfIn PDF document text
    • http://methese.com/upload/files/vukajapemezikisizajejuw.pdfIn PDF document text
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161390fe909b02---8644928157.pdfIn PDF document text
    • http://esistore.com/userfiles/file/fujer.pdfIn PDF document text
    • http://0-50.ru/userfiles/file/34041398018.pdfIn PDF document text
    • http://kolaykanal.com/userfiles/files/xowufajuf.pdfIn PDF document text
    • https://rtvpuls.com/ckfinder/userfiles/files/domifudiwilokavijej.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=tinkle+comics+free+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_off0000c512.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC512 10576 bytes
SHA-256: 3a18251556eaaa544c1ddc3f3c6fbfd63b5902e40414881f967f5c49ffe1d6be
font_01_sfnt_off0000dd21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD21 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f533.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF533 17412 bytes
SHA-256: 6c2b5294e66b1831feb1e98e816336d9b025b29fa7cd17db44e6480761ad5bf4