Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4f541b4dcf9ab8a…

MALICIOUS

PDF

81.9 KB Created: 2021-09-18 07:32:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 16ba96981c860a2e3d50d5bdf4c2cf97 SHA-1: 4897ced8c07b634163da664ee4fae99570ae076f SHA-256: b4f541b4dcf9ab8a9d044d9ff5eb937b8790890ff5da54fd31273edbc438a0ac
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by multiple heuristics as a link farm, with many URLs pointing to disposable or compromised hosting. The ML classifier and ClamAV also identified it as malicious, specifically as a phishing trojan. While no scripts were directly extracted, the nature of link farms in PDFs often involves JavaScript to redirect users, suggesting an attempt to lure victims to malicious sites for credential harvesting or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://all-paca.com/ckeditor/ckfinder/core/connector/php/uploads/files/mojakuzezamaxopimizu.pdf In PDF document text
    • http://vwtint.com/userData/board/file/zupizaxexumalebifopitu.pdfIn PDF document text
    • https://oferta.lt/i/File/76898572331.pdfIn PDF document text
    • http://0975811252cool.linker.tw/files/70289847116.pdfIn PDF document text
    • http://homeopathyhongkong.org/files/fikedubiwusarokanolu.pdfIn PDF document text
    • https://manusingh.org/scgtest/eec-new/codelibrary/ckeditor/ckfinder/userfiles/files/winavu.pdfIn PDF document text
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612f59ca25f0e---tamapijaxigij.pdfIn PDF document text
    • http://hotelpenza58.ru/ckfinder/userfiles/files/56781920461.pdfIn PDF document text
    • http://webursitet.org/Files/file/munujazapogumusiwiloxum.pdfIn PDF document text
    • http://zensushialiso.com/uploads/files/18738300548.pdfIn PDF document text
    • http://vhshf.de/File/66668499373.pdfIn PDF document text
    • https://hearing-outlet.com/uploads/files/202109020144316901.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142dfee31646---pofurobisasoveputafabud.pdfIn PDF document text
    • https://baconbites.com/wp-content/plugins/super-forms/uploads/php/files/q8r1du2jfc8fuuu6376kt0dpa1/81968445744.pdfIn PDF document text
    • https://smartbrand.ro/mm/file/20887726050.pdfIn PDF document text
    • https://bibliothequedesarts.ch/ckfinder/userfiles/files/57469912687.pdfIn PDF document text
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/16145644ebfa04---21772612882.pdfIn PDF document text
    • http://reutlinger.pl/userfiles/file/pugijunipexuki.pdfIn PDF document text
    • http://hotelbellevuepalermo.com/userfiles/files/pojuzalutoponowejaziv.pdfIn PDF document text
    • https://huanghecables.com/d/files/mofovibekiwo.pdfIn PDF document text
    • https://neurondevelopment.org/userfiles/file/kotabafexeditabirez.pdfIn PDF document text
    • https://kolegium.inaheart.org/upload/files/dajotuxepujumosu.pdfIn PDF document text
    • http://antropolog.ru/userfiles/file/negegezukivojadesabegaf.pdfIn PDF document text
    • http://farmandari-sarvestan.ir/images/news/files/64969227201.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=use+of+modals+in+sentencesPDF 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_off0000d8d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8D9 10544 bytes
SHA-256: b8a0d5c9dcc6e8944bc94f4c409b967744b42681474e8ecd7af42824b92c0eb2
font_01_sfnt_off0000f0db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0DB 18980 bytes
SHA-256: c981fa50919d2bcdb9f499b52f82736bc6fb7a68063ad320e6bd39fb1bb2f89a
font_02_sfnt_off000121c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121C3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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