Malicious PDF — malware analysis report

Static analysis result for SHA-256 5fbfffb8c94ecc15…

MALICIOUS

PDF

83.4 KB Created: 2021-09-07 22:34:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: cad8291d0b2b0704252471ed45f48fa3 SHA-1: a8a31ae118ad96d6e043bcf4b0aa1f9750e9e104 SHA-256: 5fbfffb8c94ecc15d8640080822b773e0be8adeaceb24dc7ea799793fa01ab7a
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of embedded URLs, many of which point to compromised WordPress sites hosting other PDF files. The ML classifier strongly indicates maliciousness. The document body is heavily obfuscated and unreadable, but the heuristics and URLs suggest a link farm designed to redirect users to malicious content, likely as part of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1607fb910ce9ab---6020066168.pdf In PDF document text
    • https://muzeumkonstancina.pl/attachments/file/pagusewut.pdfIn PDF document text
    • https://xn--hjrnskadeakademien-mtb.se/userfiles/file/76153293688.pdfIn PDF document text
    • https://soudurelauziere.com/upload/editor/file/limedasinifetirozosuj.pdfIn PDF document text
    • http://bagumul.com/file_upload/spaw_upload/file/20210704064649.pdfIn PDF document text
    • http://maxidmum.com/images/upload/fck/file/xusotezabalaliruz.pdfIn PDF document text
    • http://net-marketing.hu/images/files/32544220754.pdfIn PDF document text
    • http://www.zopfitravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbc5bbe1589---91430340440.pdfIn PDF document text
    • http://latexindia.com/userfiles/file/muwebuwozirapodegi.pdfIn PDF document text
    • http://brkvinc.com/userfiles/file/15482895551.pdfIn PDF document text
    • http://tubemakingmachine.com/uploadfile/files/rodifinusozavinin.pdfIn PDF document text
    • http://worksafeorg.com/wp-content/plugins/super-forms/uploads/php/files/g2in24btcl09f0u0vv2m4tnmp0/81845676558.pdfIn PDF document text
    • http://mitra.su/uploads/ckeditor/files/91550641310.pdfIn PDF document text
    • http://nissanotogovap.com/uploads/images/files/nupepafuxadadug.pdfIn PDF document text
    • http://career-id.org/ckfinder/userfiles/files/walegazo.pdfIn PDF document text
    • http://3e-machinery.ru/app/webroot/filesfiles/71959918967.pdfIn PDF document text
    • http://kleiberit.ru/files/file/zutikate.pdfIn PDF document text
    • https://bikinibody.be/wp-content/plugins/super-forms/uploads/php/files/0dcr39udm3rr6r0d14j6rf5bqo/50799961788.pdfIn PDF document text
    • http://salamino.pl/userfiles/file/vofozuzodofibutifodirozun.pdfIn PDF document text
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607d2c186c41a---60112527405.pdfIn PDF document text
    • https://canvasations.com/wp-content/plugins/super-forms/uploads/php/files/dtg739tksj4r7061648p7ar2h6/57139622067.pdfIn PDF document text
    • https://ikincielinmak.com/upload/ckfinder/files/visezuxusa.pdfIn PDF document text
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607db2151a1b5---lipexosifaturodimexar.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=aspose+java+convert+word+to+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_off0000de6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE6A 18592 bytes
SHA-256: e41dfc06031670c0d29d93cc59d756e103e1a8a5e4ea61e6f97df10b7b702062
font_01_sfnt_off00010ea6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EA6 10736 bytes
SHA-256: 7288657d4cc2a28a5622d25e09c5c4238724748ed8abb24e7261c08d1ed6bfea
font_02_sfnt_off0001279c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1279C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1