Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ba3747f7fccd498…

MALICIOUS

PDF

80.5 KB Created: 2021-09-01 15:33:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 56d261476956682f3b44d20f4a49dc34 SHA-1: 6c509d5bed6807454616fce0d4fac732c5e7b5f6 SHA-256: 4ba3747f7fccd498c08277c0a3ef8e3124ad01d8221321ccf16088dd8db0ab4a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for these links, further supporting a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://lightspec.ca/wp-content/plugins/super-forms/uploads/php/files/7f3fb03b2e7b936e26e4f6a0bb78f183/buketuvaponafubax.pdf In PDF document text
    • http://naszymsladem.pl/upload/file/zozewawijiwujeluzi.pdfIn PDF document text
    • https://anjingliar.com/contents//files/56380685322.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/161244822c416b---27155170848.pdfIn PDF document text
    • https://yocarbroker.com/upload/ckfinder/files/zujij.pdfIn PDF document text
    • http://ezibra.pl/upload//file/fitulosonar.pdfIn PDF document text
    • http://kiajihlava.cz/UserFiles/File/33159735686.pdfIn PDF document text
    • http://fotostudiovaccari.it/userfiles/files/fiwulefikuxixa.pdfIn PDF document text
    • https://www.ideaklinikizmir.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b8636aa8e3---ponutovuz.pdfIn PDF document text
    • http://zonweringbelgie.com/ckfinder/userfiles/files/4232113289.pdfIn PDF document text
    • http://torgoborud.org/images/file/87707024581.pdfIn PDF document text
    • http://dichvugiayphep.net/hinhanh_fckeditor/file/44359696092.pdfIn PDF document text
    • https://www.hamburgeriaagricola.com/wp-content/plugins/super-forms/uploads/php/files/ciq9dhgkqv9j4h6o1af8r6s22s/doruregaz.pdfIn PDF document text
    • http://nhasachnguyenvancu.com/Images_upload/files/97012847793.pdfIn PDF document text
    • https://khotelmarket.com/FileData/ckfinder/files/20210704_7B3FC73E6882AA46.pdfIn PDF document text
    • http://www.psoealora.es/ckfinder/userfiles/files/34452947848.pdfIn PDF document text
    • http://ceramicaartisticamarsalese.it/userfiles/files/10380046511.pdfIn PDF document text
    • http://relatives-united.com/clients/75139/File/96908758719.pdfIn PDF document text
    • https://braindevelopmentmaps.org/userfiles/files/matadifexawedekupasima.pdfIn PDF document text
    • http://glcore.net/ckfinder/userfiles/files/xirojapoxu.pdfIn PDF document text
    • https://mediaskills.rs//files/90181124722.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/16129df2b93021---54046657245.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=lithium+sulfate+ionic+or+covalentPDF 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_off0000d5fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5FA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ee0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE0C 17360 bytes
SHA-256: 0e6644c5ec2d649d9ac26bc13de6cfc1e743fa29cf96e8f290b0bf6d35e27698
font_02_sfnt_off00011acf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11ACF 10724 bytes
SHA-256: b38159fdc79bcb029ed63860b4ec5b2aed589c0dca281272d53087c11a58665c