Malicious PDF — malware analysis report

Static analysis result for SHA-256 5ef8c7c4ca1b4bdf…

MALICIOUS

PDF

69.1 KB Created: 2021-10-02 16:02:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 00ae740ab5d8e92cdeb044be81ff9e24 SHA-1: fd2cdb3315c6705b4d89bde3f38a29d8d4f341ee SHA-256: 5ef8c7c4ca1b4bdfd99555f284c1b3a219fd0d102e6c9344fef8185b06a338d6
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that form a link farm, with several pointing to compromised WordPress upload storage. The ML classifier strongly indicates maliciousness. While no scripts were directly extracted, the PDF structure and embedded links suggest a lure to potentially malicious websites, possibly as part of a phishing or SEO poisoning campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 5

  • 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://crysiq.ru/uplcv?utm_term=how+to+add+audio+to+screen+recording PDF link annotation
    • http://xn--365-pn7mwb654m2qn.com/ckupload/files/wiposu.pdfIn PDF document text
    • http://kimkhimientrung.com/uploads/image/files/993889840.pdfIn PDF document text
    • http://koddous.com/userfiles/file/jomagoginegopimusoruzel.pdfIn PDF document text
    • http://optimaglobal.net/ckupload/files/luwofe.pdfIn PDF document text
    • http://terhautz.com/upload_files/files/gimejiri.pdfIn PDF document text
    • http://xn--h1aeekk.xn--p1ai/files/file/96590048915.pdfIn PDF document text
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ec93538b35---43374347603.pdfIn PDF document text
    • http://gdlianyu.com/uploadfiles/file/94808178487.pdfIn PDF document text
    • http://legalinet.eu/userfiles/files/lesejuji.pdfIn PDF document text
    • http://rulada.by/upload/editor/files/53858577470.pdfIn PDF document text
    • https://dichvumayphoto.vn/webroot/img/files/83744758330.pdfIn PDF document text
    • http://www.accessibilite-salle-eau.com/ckfinder/userfiles/files/vomozenuruwegafevu.pdfIn PDF document text
    • http://palestraarkadia.it/userfiles/files/denojidipoxirizup.pdfIn PDF document text
    • https://apexforestservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/161521c245f77b---zuzosunuxopexusog.pdfIn PDF document text
    • http://leaguengn.com/userfiles/file///punimuvobujonewoxedov.pdfIn PDF document text
    • http://tantusmarina.com/UserFiles/file/81038110016.pdfIn PDF document text
    • https://senesi-sklad.cz/userfiles/file/puzisiposezulolejusalal.pdfIn PDF document text
    • http://aztkgb.love-mrt.com/upload/files/pabove.pdfIn PDF document text
    • http://technimexvn.com/images/ckeditor/files/47284449211.pdfIn PDF document text
    • https://maviet.vn/upload/files/kuniguwunufevenu.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613b1fe85b9c9---15583192267.pdfIn PDF document text
    • http://kiavysocina.cz/UserFiles/File/vipanonunudadotegixusobi.pdfIn PDF document text
    • 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_off0000ad8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAD8A 16180 bytes
SHA-256: e2961b4c6e8771f13bb30ab9ca459d0a6618a162970ce96625a6fbe5103594e0
font_01_sfnt_off0000d675.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD675 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ee8c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE8C 10676 bytes
SHA-256: 76884581ea3516a3a24b18923761848f80b9e6e6a2ab6aeda13658aeb4bedbe9