Malicious PDF — malware analysis report

Static analysis result for SHA-256 92b5775d532a3600…

MALICIOUS

PDF

81.8 KB Created: 2021-09-11 05:57:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 78320117d66d7080629eb0cdc03a834c SHA-1: b074458e5590ab49d70412490f1933e613236978 SHA-256: 92b5775d532a360024bc8c9f7eec62b5a533347192b02734480941461b1ebf3f
156 Risk Score

Malware Insights

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

The PDF contains numerous links to compromised websites, identified by heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM'. The ML classifier and ClamAV detection strongly indicate malicious intent. The embedded URLs likely serve as lures to phishing pages or further malware downloads, aligning with a spearphishing attachment attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/efbd2167dd6ce8fc436eb8c643cea1ea/49417324039.pdf In PDF document text
    • http://metisentry.net/ckfinder/userfiles/files/kamilitotis.pdfIn PDF document text
    • https://manajrgvaaradhi.com/cms-uploads/files/89620610936.pdfIn PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612eb9610bd04---10826433282.pdfIn PDF document text
    • http://koovappadyscb.com/ckfinder/userfiles/files/5134303689.pdfIn PDF document text
    • http://biosafety.biz/ckfinder/userfiles/files/93858059440.pdfIn PDF document text
    • https://citytrafik.nu/images/file/6425575449.pdfIn PDF document text
    • https://5udua.com/contents/files/8406380619.pdfIn PDF document text
    • https://ecableapp.com/FCKeditor/FCKimgUpload/file/50358880725.pdfIn PDF document text
    • https://rajakeempat.com/contents/files/loginelafir.pdfIn PDF document text
    • http://hak-al.com/resimler/files/5710206037.pdfIn PDF document text
    • https://binarbaidrealestate.com/public_html/userfiles/file/wewexunikusev.pdfIn PDF document text
    • http://staractivecollection.com/resimler/site/files/revobevusopubodut.pdfIn PDF document text
    • http://jiachuankeji.com/upload_fck/file/2021-9-11/20210911000522496231.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/0682b818f795b26a14e413d2f069be93/43475273416.pdfIn PDF document text
    • https://grdr.org/paidel/ckfinder/userfiles/files/20882607258.pdfIn PDF document text
    • https://www.thecandystoresudbury.com/wp-content/plugins/super-forms/uploads/php/files/a5k7v5mv6nohkbtkec54tmigct/7929142856.pdfIn PDF document text
    • http://fractinvest.com/uploads/file/5123253392.pdfIn PDF document text
    • https://rhdplumbing.com/wp-content/plugins/super-forms/uploads/php/files/bc8b408ce6a6bd09264035a9679f853b/52708119820.pdfIn PDF document text
    • http://tottazo.com/userfiles/file/44347815583.pdfIn PDF document text
    • https://haisanquangninh.org/data/dulieu/files/93374768082.pdfIn PDF document text
    • http://pekingtogo.com/uploads/files/19071365269.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=brain+training+dr+kawashima+app+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://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_off0000db74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB74 17484 bytes
SHA-256: e698f4e9151379bb9a16ca26ce2fe5e0990dd2a8c4ad51f2a4479e985fbf6785
font_01_sfnt_off00010901.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10901 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012118.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12118 10892 bytes
SHA-256: e0e03972e05a4d021b69504afe00e6325b65f8ee7b278340888408f54f90cc20