Malicious PDF — malware analysis report

Static analysis result for SHA-256 653c8fb5b61986e3…

MALICIOUS

PDF

86.7 KB Created: 2021-09-18 18:49:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: ef1ef94b5d4859e34a415e3df90c6e24 SHA-1: 47511719c21e4853e33990591a283b802d41b07f SHA-256: 653c8fb5b61986e38ae28e768f65879321d04f50f8f37f6d6318e3eb620540c7
96 Risk Score

Malware Insights

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

The PDF file was identified as malicious by an ML classifier and contains numerous embedded URLs. Several heuristics indicate that this PDF functions as a link farm, with many links pointing to compromised WordPress uploads or disposable hosting domains. The primary purpose appears to be directing users to external sites, potentially for SEO spam or to host further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9979

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://braveathlete.net/geektic/files/93849806547.pdf In PDF document text
    • http://gewoongroen.eu/app/webroot/files/userfiles/files/xudogo.pdfIn PDF document text
    • http://ahzycw.com/upload_fck/file/2021-9-14/20210914084834422320.pdfIn PDF document text
    • http://chayka-svg.ru/files/teminibosal.pdfIn PDF document text
    • https://people11people.com/uploads/File/lujisuje.pdfIn PDF document text
    • http://bagiez.com/userfiles/file/30312114970.pdfIn PDF document text
    • http://libertyquad72.fr/userfiles/file/pevido.pdfIn PDF document text
    • https://laneopx.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135008984251---fizadeko.pdfIn PDF document text
    • http://labellebeaute.com.hk/ckfinder/userfiles/files/7270273008.pdfIn PDF document text
    • https://receptabc.hu/images_banner/files/40832941258.pdfIn PDF document text
    • http://abwlanham.com/uploads/files/miviwuzulupazaruzama.pdfIn PDF document text
    • http://dainichiji.com/upload_ckr/files/19156721919.pdfIn PDF document text
    • http://blevy.com/ckfinder/userfiles/files/piliba.pdfIn PDF document text
    • http://inistor.com/ufiles/files/kupes.pdfIn PDF document text
    • http://peetersinstallatietechniek.nl/upload/files/gedetumatis.pdfIn PDF document text
    • https://ltes2.tw-goods.com/UserFiles/files/3987139082.pdfIn PDF document text
    • https://vzglavniki.net/data/file/82788817280.pdfIn PDF document text
    • http://hockjoohin.com/admin/uploads/file/sivutitemu.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/16136429fc7a11---23448164252.pdfIn PDF document text
    • http://autosoftware.company/autoresponders_images/files/18785046453.pdfIn PDF document text
    • https://concurs-euclid.ro/upload/fck/samotomaves.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d91ce8fac0---rudovuwawunan.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=spider+man+far+from+home+movie+in+telugu+downloadPDF 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_off0000eb7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB7B 11104 bytes
SHA-256: 001522c23d92cb14f068f22ed46610ad3a9f7d2b8da5e57a10c2d7569c0fc433
font_01_sfnt_off000104fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104FA 18368 bytes
SHA-256: 6bfd12a94eac730877f79b5953cfe5af5ffb3b5ce854d52e6fb71713f2cf00c2
font_02_sfnt_off000134a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x134A8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1