Malicious PDF — malware analysis report

Static analysis result for SHA-256 520c4e1eac504aa7…

MALICIOUS

PDF

87.4 KB Created: 2021-08-20 22:45:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 6ffaf6c0270419b62e783cd59e27a7db SHA-1: 7d71c3542357f151c158879dd5e616f957b03e8e SHA-256: 520c4e1eac504aa716efcbd646c3a31c6a946658c73cc33de03ebd57388b28b6
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, many of which point to compromised WordPress upload directories or disposable hosting, indicating a link farm designed to distribute malicious content. ClamAV detection and ML classification strongly suggest malicious intent. The file's structure and URL distribution align with phishing or malware distribution tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9896

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://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607144870022e---wexilisuzegiruxovix.pdf In PDF document text
    • https://recrut.com/files/files/49384489541.pdfIn PDF document text
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607fb9a53d97e---jesokabekekuforanuzab.pdfIn PDF document text
    • https://goldenparadisestsimons.com/wp-content/plugins/super-forms/uploads/php/files/08ffb8fac6ce9d2142a3c67d9c774a5c/61909603615.pdfIn PDF document text
    • https://mamo-tato.ro/userfiles/file/63206317074.pdfIn PDF document text
    • http://lso-msm.fr/userfiles/file/71680610994.pdfIn PDF document text
    • https://gauravkankariya.com/wp-content/plugins/super-forms/uploads/php/files/82af683auqk6aog3ul9gf4onp4/koronefovatuditu.pdfIn PDF document text
    • http://ctyrkolky-gamax.cz/data/dokumenty/26239046298.pdfIn PDF document text
    • http://eastmoorclassof1970.com/clients/4/43/4343e427eb1b0a0668350338a4d6b623/File/1691274656.pdfIn PDF document text
    • https://cowichanmusicfestival.com/userfiles/file/vedopubuginoxodi.pdfIn PDF document text
    • http://www.eurosecurimed.com/ckfinder/userfiles/files/difopikuxuxisurejugus.pdfIn PDF document text
    • http://zoncmswebsitebeheer.nl/files/editor/file/mabakajesiwuj.pdfIn PDF document text
    • http://entone.es/wp-content/plugins/super-forms/uploads/php/files/197d9934a5090e5e92145ceaee613f2f/fujemegaxegezuxowidelapil.pdfIn PDF document text
    • http://congtyvima.com/images/Download/7137069252.pdfIn PDF document text
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e94926644c---senudutedugazafi.pdfIn PDF document text
    • https://clickkedai.com/userfiles/file/ziredimitirokukuf.pdfIn PDF document text
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090805aded40---bomajagafagiso.pdfIn PDF document text
    • http://medica-brno.com/files/ziwedososajojo.pdfIn PDF document text
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1607022dff03f6---28004602992.pdfIn PDF document text
    • https://0800-707-808.com/upload/ckfinder_temp/files/20210725222456.pdfIn PDF document text
    • http://wonikqnc.com/upload/editor/file/1627897739.pdfIn PDF document text
    • https://haidangpc.com/contents/files/norujosu.pdfIn PDF document text
    • http://vudafrique.com/wp-content/plugins/super-forms/uploads/php/files/5b773e3b3720541b81fe1b5be2be3c75/26309569643.pdfIn PDF document text
    • https://balajitutorial.com/admin/userfiles/file/walobobubonekupada.pdfIn PDF document text
    • http://xnucleus.com/members//member_images/files/21952308025.pdfIn PDF document text
    • https://vetamblj.si/ckfinder/userfiles/files/22230058298.pdfIn PDF document text
    • http://clinicaveterinariamontecchia.com/userfiles/files/22967837295.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=aye+axemen+orientation+bookPDF 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_off0000efd8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFD8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000107ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107EA 17800 bytes
SHA-256: b200efc31a98519cc0e94f7c19c1e224d845a82b9eb726fe04990d961c9ec5a5
font_02_sfnt_off000136aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136AA 10484 bytes
SHA-256: 07d2bed4d2661a5bd130c77d9b83820bdf4e5a4b2fdf07588bf4e93fe02fcab7