Malicious PDF — malware analysis report

Static analysis result for SHA-256 7a6ec85e6178b9ef…

MALICIOUS

PDF

81.9 KB Created: 2021-09-05 14:22:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: a7c4e9cfb1353df9ac8f86a958ea2f60 SHA-1: e132a69a9c54d3611dcf79e3d461cd272bd3ead4 SHA-256: 7a6ec85e6178b9ef36833232346c1ab0076ecd5ac78014ff06ddf2d7b4fea318
96 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites and other domains, suggesting a link farm or redirection scheme. The ML classifier strongly indicated maliciousness, and the presence of multiple links to potentially compromised CMS upload directories supports this. No scripts were extracted, but the overall structure and URL distribution indicate a malicious intent to redirect users to external, potentially harmful, content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://gdwtechnology.com/fckeditor/file/zawusiziwiga.pdf In PDF document text
    • https://www.mybizwebsites.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609190e7e084b---nizojufijaponatem.pdfIn PDF document text
    • https://agroadvanced.com/app/webroot/newsletters/editor/files/zejomubijazerudefoz.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160cfc94a1b3d3---40487585356.pdfIn PDF document text
    • http://020tzs.com/baige/images/userfiles/file/75541244801.pdfIn PDF document text
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16090c8da83a27---75261026304.pdfIn PDF document text
    • https://dichocungtoi.com/userfiles/file/refojezivoz.pdfIn PDF document text
    • https://widepolymers.com/userfiles/file/40759996257.pdfIn PDF document text
    • https://bladmedyczny24.pl/wp-content/plugins/super-forms/uploads/php/files/676bc2e1df1db99c916510dbd39c8859/1281665081.pdfIn PDF document text
    • http://elcivan.com/admin/UserFiles/file/74247023678.pdfIn PDF document text
    • http://tbvshungviet.com/upload/files/8471498280.pdfIn PDF document text
    • http://leadingedgecorporate.com/user_images/file/98672445726.pdfIn PDF document text
    • http://quanhoangtsi.com/upload/quangtri/files/madukis.pdfIn PDF document text
    • https://voolabs.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d007aa48b21---ganudow.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1608367668bd56---lesowupifulilij.pdfIn PDF document text
    • http://qiangka.com/ckfinder/userfiles/files/5004686076.pdfIn PDF document text
    • https://unovosti.tv/ckfinder/userfiles/files/xabavemalelenojefofu.pdfIn PDF document text
    • http://kerrya.com/ckfinder/userfiles/files/kunemujibirifugujux.pdfIn PDF document text
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/160a78a3c1d987---novediruwe.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1607d8d77edf0f---xoranurafimobexubefipulug.pdfIn PDF document text
    • https://empylean.com/wp-content/plugins/super-forms/uploads/php/files/alg9e7b6r1vovdibnig3vgjf03/95538854696.pdfIn PDF document text
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/0cf14faeedfc0585514902aa288ce90d/40714176483.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=curriculo+primeiro+emprego+pdf+2018PDF 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_off0000d8dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8DD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f0f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0F4 11064 bytes
SHA-256: 5beb7edcef48336f8a2e442f93f8f1c9e74fb97074715df804b02bd21df810e3
font_02_sfnt_off00010a94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A94 18056 bytes
SHA-256: 6f56cda176f91f497774fdca8a602acb5f0aaa8b013c7ae0ecd7f5a98c9cd511