Malicious PDF — malware analysis report

Static analysis result for SHA-256 ad1c1a19e6b4e5e4…

MALICIOUS

PDF

75.3 KB Created: 2021-09-07 20:13:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 08f348d32feb66d188421b145d4d2334 SHA-1: d9c6ff85fa062fac85d81b549a8edf68d55d3c45 SHA-256: ad1c1a19e6b4e5e4a817e7f477ba3ad5608c1a1709e1bf9fb0b11c827d84a6e9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to numerous distinct hosts, many of which appear to be compromised WordPress sites or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to host malicious content or redirect users to phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9914

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://vieclamlaocai.vn/webroot/img/files/mesewojepuma.pdf In PDF document text
    • https://trsbarriersdirect.com/wp-content/plugins/super-forms/uploads/php/files/kf5ahq4dfo6sdfnh7g8gp3ii2p/64555991292.pdfIn PDF document text
    • http://bikipvuikhoedep.com/app/webroot/files/editor_upload/files/bufurugupasemol.pdfIn PDF document text
    • http://2478.ru/admin/ckfinder/userfiles/files/nonitomigof.pdfIn PDF document text
    • https://csom.cz/wp-content/plugins/super-forms/uploads/php/files/3cc11642821503ea701ad57385db3c0b/55928437445.pdfIn PDF document text
    • http://moto-bike.pl/userfiles/file/77955587547.pdfIn PDF document text
    • http://caythuocdangian.net/images/files/94441151767.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/bg5etdpo3d6h0gejcnb6ddcevf/vomijexiguxi.pdfIn PDF document text
    • http://www.photobreak.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607687bfeaed7---11651649407.pdfIn PDF document text
    • http://fsoa.cn/userfiles/file/dogugopo.pdfIn PDF document text
    • https://nhanloc.net/userfiles/file/81645358964.pdfIn PDF document text
    • http://johnmarzillier.com/ckfinder/userfiles/files/61099059601.pdfIn PDF document text
    • http://www.miamiairportlimo.net/wp-content/plugins/formcraft/file-upload/server/content/files/160772a638b311---tufezajug.pdfIn PDF document text
    • https://www.marbelitesa.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a2683f8f59a---dazilo.pdfIn PDF document text
    • http://hungbuloon.com/media/ftp/file/bemukodimamoneke.pdfIn PDF document text
    • http://brunagabriele.it/userfiles/files/zinonedonubobubomevupom.pdfIn PDF document text
    • http://asja-doll.ru/userfiles/file/wexalawuraxilibuvob.pdfIn PDF document text
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160adc4e2c8d74---guzoreneges.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/16099b49b2b55f---jexakewo.pdfIn PDF document text
    • https://www.adom.biz.pl/ckfinder/userfiles/files/jepataderugomikobez.pdfIn PDF document text
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b9b953df671---71362543264.pdfIn PDF document text
    • http://globalfeedindustry.com/upload/files/298584585.pdfIn PDF document text
    • http://loaamtran.com/files/usersfiles/files/somozewebib.pdfIn PDF document text
    • http://www.awakohchang.com/image/upload/File/1793251370.pdfIn PDF document text
    • http://mirutte.com/newsfiles/files/69869967807.pdfIn PDF document text
    • https://bechtoldpaving.com/wp-content/plugins/super-forms/uploads/php/files/d219f515c5766e625f76df747d6196de/76112755856.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=15.2+pollution+of+the+atmosphere+worksheet+answersPDF 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_off0000c03b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC03B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d84d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD84D 16888 bytes
SHA-256: 488c2e7828cd76363e952789fda115f229cd9b0c99b0d93e68d6d017b092c492
font_02_sfnt_off000102f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102F3 11176 bytes
SHA-256: 5a09538baff9b5ace1e02e1be7e2a34e38996948607d50c7362764c070342766