Malicious PDF — malware analysis report

Static analysis result for SHA-256 a85792b498de2512…

MALICIOUS

PDF

73.0 KB Created: 2021-05-09 09:10:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 2d4ef64affba5ddff6803c11ab8d551f SHA-1: fa528cf91f5b004574b01bc045374071ffca86b6 SHA-256: a85792b498de25127cbf8b6aefe9378fd7d9cae0609b9503b92061d9b315ba5b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to compromised CMS upload storage and disposable hosting, suggesting a link farm designed to distribute malware or facilitate phishing. The presence of embedded URLs and the nature of the heuristics point towards a phishing or malware distribution campaign, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/4ht5622vh1rnrbg372afoajk09/79408502886.pdf In PDF document text
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160889b03563d3---31164579140.pdfIn PDF document text
    • https://pablohernandes.com/wp-content/plugins/super-forms/uploads/php/files/9ab2ec1992efd7d55b82119a3043e3fb/lovomozizutilejeseliziga.pdfIn PDF document text
    • http://www.empresasdelimpeza.info/wp-content/plugins/formcraft/file-upload/server/content/files/16076f5f96098e---59544786317.pdfIn PDF document text
    • https://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/160845527f3571---xalopoluju.pdfIn PDF document text
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16085a4822722f---lifasatokugigilabiwe.pdfIn PDF document text
    • https://www.isgs.org/wp-content/plugins/super-forms/uploads/php/files/8172acfeb4343501a4b95fc2f8ec8d85/gajisiketonetakep.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/kq4spku15mrn0edmf97ur0qc12/tafisovepurevegosapamej.pdfIn PDF document text
    • http://fashioncenterpoint.com/wp-content/plugins/super-forms/uploads/php/files/034b2b7ce8948535897ceb3e796de49e/xodudapinejarixonamuboxu.pdfIn PDF document text
    • http://www.atrium-tuiles.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088176abce71---pavowududepafu.pdfIn PDF document text
    • https://davebakeragency.com/wp-content/plugins/super-forms/uploads/php/files/4460cdb150662a029c3d941931e34dec/fobapadug.pdfIn PDF document text
    • http://alphabodysupplements.com/newerac2c/userfiles/file/fafunobodisorinupof.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608afff30b6fc---52947759002.pdfIn PDF document text
    • https://freedomhypnosisnyc.com/wp-content/plugins/super-forms/uploads/php/files/bbcbed45687b018052ad6cd74155cc35/66564119631.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=safe+caller+id+app+for+androidPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e27c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE27C 5072 bytes
SHA-256: 1f123087da645b669aa5d5fb1df830e15ce0def6c5c7dd23d0e7fc5d89510cb3
font_01_sfnt_off0000f3cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3CF 10408 bytes
SHA-256: 7e3f42b57abcf31f3e41e33e271f82811fda828926096bcad9cc39736390c8da