Malicious PDF — malware analysis report

Static analysis result for SHA-256 db8f82421a9a4be8…

MALICIOUS

PDF

69.0 KB Created: 2021-09-06 03:20:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: f0dd395d5af92e6c935709e9bfc5301c SHA-1: e71a15b6004cf78508daec9b3b1ecdea62fc23de SHA-256: db8f82421a9a4be8753218660f6aefa8cd39f5d2d32de5eef22beaec41f893fb
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and contains embedded JavaScript. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://synerhu.ru/uplcv?utm_term=el+metodo+constantin+stanislavski+pdf PDF link annotation
    • https://www.emma-solutions.de/wp-content/plugins/formcraft/file-upload/server/content/files/16080dc5dac9c1---mopizojizefujimiduloda.pdfIn PDF document text
    • http://eshop-kocicinadeje.cz/files/file/75708119959.pdfIn PDF document text
    • http://to-kajihan.net/js/upload/files/22588694574.pdfIn PDF document text
    • http://interno-kazan.ru/upload/files/rakiv.pdfIn PDF document text
    • https://www.lorenzofranzone.it/wp-content/plugins/super-forms/uploads/php/files/2b7109877bbb555ac372815e9659b0b5/tomoxuxawowanofifuruwu.pdfIn PDF document text
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/tm8n8r0eui4ca4tp6r7vp7e2vm/xabulitunupo.pdfIn PDF document text
    • http://lasfyy.com/uploadfile/file/20210626164543300.pdfIn PDF document text
    • https://charterfori.ir/basefile/charterforiir/files/bamubanunedokewa.pdfIn PDF document text
    • http://ubest.ru/images/file/56401084056.pdfIn PDF document text
    • http://kolesnikov.pro/ckfinder/userfiles/files/42416494718.pdfIn PDF document text
    • http://gzcil.com/uploadfile/files/jenuvapazofevujux.pdfIn PDF document text
    • https://gbagencement.fr/uploads/file/zepukud.pdfIn PDF document text
    • https://hanomanberjaya.com/contents//files/99471149737.pdfIn PDF document text
    • https://afanasyev-design.ru/wp-content/plugins/super-forms/uploads/php/files/0f60652ba164742bb1e001c473e8f856/gubam.pdfIn PDF document text
    • https://festivalecolo.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607e50139f2e0---wuvufejesatuxadotefojo.pdfIn PDF document text
    • http://www.chatanakonci.cz/userfiles/file/39905837059.pdfIn PDF document text
    • http://kernenshepler.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/90218676861.pdfIn PDF document text
    • http://sz-nuoyi.com/Upload/file/2021072814382229312.pdfIn PDF document text
    • https://plumcourse.com/wp-content/plugins/super-forms/uploads/php/files/952d1a894466ad908c8d86ccd9bfa894/doxalukamaberetipozitul.pdfIn PDF document text
    • http://www.accessibilite-salle-eau.com/ckfinder/userfiles/files/62636757329.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_off0000aea4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAEA4 15184 bytes
SHA-256: 90dac26393af55c83f8d6d57a013d44e16357d133cce0e798f4532649a233503
font_01_sfnt_off0000d54a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD54A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ed61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED61 10824 bytes
SHA-256: 9d6acdd61f59d3a05580fa9262dbea33cfe0e1455cb8ec80dbccd59aedf84c25