Malicious PDF — malware analysis report

Static analysis result for SHA-256 839adfdce4e5b431…

MALICIOUS

PDF

74.6 KB Created: 2021-05-25 11:47:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-27
MD5: d554637f73e84c06c561fbe5b9f002d9 SHA-1: 108627f940f0850119b7982262393042eb405e61 SHA-256: 839adfdce4e5b431a934d68ab5a4594d80abb5a9170531b5c669e47fbc5f46a5
96 Risk Score

Malware Insights

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

The PDF document contains numerous links to compromised WordPress sites, suggesting a link farm or SEO poisoning tactic. The document body, though heavily obfuscated, appears to be related to search terms, further supporting the lure of a malicious website. The ML classifier strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://wastran.ru/uplcv?utm_term=what+bible+says+about+mother+in+laws PDF link annotation
    • https://pankalconstructora.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093a5d6a5d07---foriwa.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ab0a4f1edfa---81154077678.pdfIn PDF document text
    • https://www.asahinadigital.com/wp-content/plugins/super-forms/uploads/php/files/t5rq9a68v579fnmgr9f1c4pc9o/samuvixorikosogo.pdfIn PDF document text
    • https://gpagroup.in/wp-content/plugins/formcraft/file-upload/server/content/files/1607b40eab94d7---koname.pdfIn PDF document text
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cae9a9f51c---18803191353.pdfIn PDF document text
    • https://medtek.vn/storage/file/60162191580.pdfIn PDF document text
    • http://www.suffaheducation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160843d17c15f9---difez.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16081098da19d5---83755202988.pdfIn PDF document text
    • http://adance0112.com/upfile/editor/file/wototakakopigu.pdfIn PDF document text
    • http://lifemartrealestateconnect.com/wp-content/plugins/super-forms/uploads/php/files/hm6s3k81h5hg4kf2pl7udu9517/27890904950.pdfIn PDF document text
    • https://www.parkgest.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160870323d7490---wuloluweroraripafiminumi.pdfIn PDF document text
    • http://tavernadelsnoguers.com/wp-content/plugins/super-forms/uploads/php/files/52c67c56320a589db6e04cf1b2b85b60/91123383965.pdfIn PDF document text
    • http://www.tecnotrefg.it/wp-content/plugins/formcraft/file-upload/server/content/files/160ab32b517197---zexopufifojabarude.pdfIn PDF document text
    • http://taxicityplus.ru/userfiles/file/fexugemexukere.pdfIn PDF document text
    • http://rajskiewakacje.pl/userfiles/file/semidugufada.pdfIn PDF document text
    • http://mousike.it/img_ins/files/93355739939.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/2411c87cf00953da348d3debcaae342a/vulujomizonudem.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e69f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE69F 5272 bytes
SHA-256: da0e071b64bf9afd6330b8785128424cf742f41a7ad8155b873be9ed4eb3b702
font_01_sfnt_off0000f875.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF875 10900 bytes
SHA-256: 6265f16110d53673350ac4397c162a8d063e0d50631789b76913be9bab00e606