Malicious PDF — malware analysis report

Static analysis result for SHA-256 921bd2bde42b47d2…

MALICIOUS

PDF

100.1 KB Created: 2021-08-21 11:09:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 86660fcc78fbcdca9de4d460e0b24bb5 SHA-1: d4228740882d12cb40b6462c42194d04093cf3e7 SHA-256: 921bd2bde42b47d2b12c81f2dd13892f0352e721b910aa0cc53bca10398758cd
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 hosting PDF files. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically identified as a phishing trojan. The presence of link farms on disposable hosting and compromised CMS uploads suggests an attempt to distribute malicious content or phish users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608118982faa3---potodudurimumadatule.pdf In PDF document text
    • https://anhhuynoithat.com/asset/files/49930238904.pdfIn PDF document text
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/64af564617d2cb721fd20ed0a125a968/joxubozedidekono.pdfIn PDF document text
    • https://www.hinogas.com/wp-content/plugins/super-forms/uploads/php/files/r1m7kbbu51hn80frc3v11v6ijf/xekifasud.pdfIn PDF document text
    • https://facades-et-traditions.com/actualites/file/davebak.pdfIn PDF document text
    • https://simondaulte.com/ckfinder/userfiles/files/tanevemulal.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/16080d653d9073---kipejeritozivadala.pdfIn PDF document text
    • http://veterinariomauracotti.it/userfiles/files/dibularu.pdfIn PDF document text
    • https://kindliving.org/wp-content/plugins/super-forms/uploads/php/files/tmp/67265546446.pdfIn PDF document text
    • https://delcinfo.ru/img/files/files/91540159849.pdfIn PDF document text
    • http://yoron.net/up/files/32081622059.pdfIn PDF document text
    • http://adance0112.com/upfile/editor/file/wepifuxomazugemasep.pdfIn PDF document text
    • http://gdwtechnology.com/fckeditor/file/gosorexoxirotopomuli.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/1608b507198619---9114048500.pdfIn PDF document text
    • https://www.beewellrx.com/wp-content/plugins/super-forms/uploads/php/files/tmp/26654649747.pdfIn PDF document text
    • http://www.tobywells.org/media/fckdir/file/bofofukupupo.pdfIn PDF document text
    • http://kingsfinancialconsulting.com/userfiles/file/kamuwemokijif.pdfIn PDF document text
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/511132082478703542213ca9539fd265/jorulefoxadepawukabuva.pdfIn PDF document text
    • http://tumwebthailand.com/ckfinder/userfiles/files/zarudu.pdfIn PDF document text
    • http://adria-ex.com/images/blog//file/90937830238.pdfIn PDF document text
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f2ffecf23b2---17149431414.pdfIn PDF document text
    • http://avonsteel.com/UserFiles/file/fasojekovawo.pdfIn PDF document text
    • http://naszymsladem.pl/upload/file/89249250401.pdfIn PDF document text
    • http://madmojo.com/fckupload/file/97095500469.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=pruebas+bioqu%C3%ADmicas+para+enterobacterias+tablaPDF link annotation
    • https://sharpspringwww.kinsta.cloud/wp-content/plugins/super-forms/uploads/php/files/3fe191bdfabf4de7e355b1a16c5605aa/tinimozezakezeto.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_off00011f04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F04 10984 bytes
SHA-256: bc75f6f4c1db0b4cf057f9de50771014c7faae3d4d630e7bbfe30bf58b5e4560
font_01_sfnt_off00013845.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13845 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015057.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15057 18392 bytes
SHA-256: 4b743e065b247990773fdd730e1537f76339388e82ba7bf535cc351277400e93