Malicious PDF — malware analysis report

Static analysis result for SHA-256 e1821f1adb7d3523…

MALICIOUS

PDF

76.8 KB Created: 2021-07-22 14:15:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 18ea87a8c77dccd99170d61e92d87846 SHA-1: b81ded5ca3c0f6490414a6ad89b0bb22e2f8fe94 SHA-256: e1821f1adb7d352380e82d2cfdba30dcbe2138fc3d640119492423ef3a7e4c84
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of links pointing to various websites, many of which are hosted on compromised CMS platforms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The file's structure as a link farm suggests it's designed to lure users to external, potentially malicious, content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://pensiunea-escape.ro/ckfinder/userfiles/files/zumesafebefudofafus.pdf In PDF document text
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac0ae048e80---fatorokefanosuniligi.pdfIn PDF document text
    • http://svsteinfurth.de/radsportfiles/file/86441264996.pdfIn PDF document text
    • http://debsluxe.com/clients/1/17/174397649ed9f07baa8f9d9f48c72a4d/File/birelidewuri.pdfIn PDF document text
    • http://ahkjt.com/upfile/file/vaforarogepefi.pdfIn PDF document text
    • http://ahrestygz.com/userfiles/files/20210629_001031.pdfIn PDF document text
    • https://bustotoronto.com/userfiles/file/89227637869.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/160b0688932f17---garuranorinepo.pdfIn PDF document text
    • https://urbanplace.me/wp-content/plugins/super-forms/uploads/php/files/011c56f80d10b612c5fa01aedab6b93c/65876589421.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/160adcbc06082e---23708739421.pdfIn PDF document text
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/3a7eabc0a5786bd8030e1518453bd26d/bixiju.pdfIn PDF document text
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/16090e96b2d602---rajisije.pdfIn PDF document text
    • https://edoxmarketing.com/wp-content/plugins/super-forms/uploads/php/files/412h0cc1bh7pifba19inql5upu/sutuwaguledopekumuladera.pdfIn PDF document text
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/14dab304e02847d152beb63110d9a949/vinolemo.pdfIn PDF document text
    • http://luluscafeonline.com/uploads/files/pevajolezebofesebisabiz.pdfIn PDF document text
    • http://hzzxtl.com/UploadFile/file/20210704040222341.pdfIn PDF document text
    • http://coreaad.com/DreamDataUpload/file/81557234075.pdfIn PDF document text
    • http://naturallabs.fr/userfiles/file/94276790410.pdfIn PDF document text
    • http://fullcolorspandoeken.nl/userfiles/file/sibokalugarumav.pdfIn PDF document text
    • http://sequoia59.com/clients/867919/File/51281549504.pdfIn PDF document text
    • https://www.tifdip.com/wp-content/plugins/formcraft/file-upload/server/content/files/160905883be5e4---41652294953.pdfIn PDF document text
    • https://space1500.com/wp-content/plugins/super-forms/uploads/php/files/e3c73d8de382de38dc93889895ecdbd2/10147105424.pdfIn PDF document text
    • https://zazilha.com.mx/wp-content/plugins/super-forms/uploads/php/files/7e658fe6cdfa2f9d790b804432b9eab3/36411891048.pdfIn PDF document text
    • http://orderbestwings.com/uploads/files/26011481130.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/t38uee62f65bu101t1je8stvn0/bumoderozosedejajetidokod.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=and+in+c+programmingPDF 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_off0000cbc8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBC8 10392 bytes
SHA-256: 727b5ad96201c6b3b2d4bd7102f4ad45824c92a4efdb9f1d0666687e4a72e14a
font_01_sfnt_off0000e2ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2FF 16668 bytes
SHA-256: 6804569f8ee98facdc9011b84fe82ef792fd773058a5bd719d56c1c5fd9f94cd
font_02_sfnt_off00010da2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DA2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1