Malicious PDF — malware analysis report

Static analysis result for SHA-256 2fb6dba0aed9f137…

MALICIOUS

PDF

79.5 KB Created: 2021-09-19 10:18:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: dc8aebbf34b6421336c2a6aab0865eb8 SHA-1: ccc8369843a77e520734dc30f1921594beefd75a SHA-256: 2fb6dba0aed9f1376d743a49ed7f85a3d6c7a1d63fd1c0e90afe24818f82eadb
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to other PDF files hosted on various domains. Several heuristics indicate this is a link farm, with some links pointing to compromised CMS upload directories. The ML classifier strongly suggests maliciousness, and the overall structure points towards a campaign to distribute further content or manipulate search engine results.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://jinsonmetal.com/Upload/file/jewuvapokafijoxudezozu.pdf In PDF document text
    • http://cmrivestimenti.com/userfiles/files/821828653.pdfIn PDF document text
    • http://abwingsbuffalo.com/uploads/files/wunutizenegivo.pdfIn PDF document text
    • http://bagiez.de/userfiles/file/85345080773.pdfIn PDF document text
    • http://ar-intl.net/wp-content/plugins/super-forms/uploads/php/files/c2jac6eitsae6dn03rdpicbmo6/javinirid.pdfIn PDF document text
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16146a0c31d644---jifitaxenuxobepukosole.pdfIn PDF document text
    • https://sellos-mecanicos.com/wp-content/plugins/super-forms/uploads/php/files/3e9717e664c702d8fee0f2ea1c4e9f2c/nadefot.pdfIn PDF document text
    • http://phutunggiahungoto.com/uploads/files/tupako.pdfIn PDF document text
    • http://gallery4walls.com/upload/editer/file/roredabipunurusivojorune.pdfIn PDF document text
    • http://thefutureofgolf.eu/wp-content/plugins/formcraft/file-upload/server/content/files/161424e7445c1c---zajenisoxub.pdfIn PDF document text
    • https://alwillislifecenter.org/ckfinder/userfiles/files/11632836842.pdfIn PDF document text
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16140542302cae---92168498963.pdfIn PDF document text
    • http://1000projects.ru/upload_picture/file/gevaminodiwus.pdfIn PDF document text
    • http://www.nomorcantikjoss.com/file/saxat.pdfIn PDF document text
    • http://videotour24.com/data/fckupload/file/85925987793.pdfIn PDF document text
    • http://autosoftware.company/autoresponders_images/files/kemorebusovenadutu.pdfIn PDF document text
    • http://phupmirpol.pl/userfiles/file/disele.pdfIn PDF document text
    • http://keralabiblesociety.com/fck_uploads/file/78286871779.pdfIn PDF document text
    • https://censcakmu.org/board/file/files/18473320107.pdfIn PDF document text
    • https://shriayurvednagpur.org/public/ckfinder/userfiles/files/5718544477.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/1aec0678da8829350980e09c89c91506/guzovidojewavam.pdfIn PDF document text
    • http://balassalaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/jasimibizenexibovoxid.pdfIn PDF document text
    • https://xn--78-6kce7dfhb9dwb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/2b15d4bdee5caf7101250821ff118f6b/nefozovavox.pdfIn PDF document text
    • http://gesgo.de/userfiles/file/duxafejorekafenog.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=openload+movies+linkPDF 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_off0000cf9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF9A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e7b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7B1 10536 bytes
SHA-256: ae677c908e28384c03609477498f271af80353a143183bf3ff7902408dbd9bed
font_02_sfnt_off0000ffac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFAC 18824 bytes
SHA-256: 97ea46ab239597d03365de5334ff19ec501b8bbaf8b0dfa678458ead32c7dac3