Malicious PDF — malware analysis report

Static analysis result for SHA-256 87f8ac99ba59c13d…

MALICIOUS

PDF

75.5 KB Created: 2021-09-17 01:44:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: d8fa7de7f1981c5a6c35cb4e279ba5d2 SHA-1: cf3e38c99a7bd71a211e5a04488fa982a1e591dd SHA-256: 87f8ac99ba59c13df6d484f39688f5a2d3b8c74434636085731ec83d148944fd
134 Risk Score

Malware Insights

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

The sample is a PDF file flagged by multiple heuristics, including a critical ClamAV detection and a high ML score, indicating malicious intent. The presence of embedded JavaScript and a large number of external URLs, many pointing to disposable domains, suggests a phishing or malware distribution scheme. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this by identifying the document as a link farm on disposable hosting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://queure.ru/uplcv?utm_term=get+data+back+for+android PDF link annotation
    • https://brakos.it/file/siwazazasopimir.pdfIn PDF document text
    • http://boilerservis.ru/uploads/files/12223372466.pdfIn PDF document text
    • http://bolt.fo/public_html/userfiles/files/61807813498.pdfIn PDF document text
    • https://parkettworld.com/upload/files/zexexasipajuz.pdfIn PDF document text
    • http://musicfriend.vn/public/default/ckeditor/files/rolanixofif.pdfIn PDF document text
    • http://toyotarent.hk/FileData/ckfinder/files/20210916_698624989E621797.pdfIn PDF document text
    • http://unewstoday.com/task/userimages/file/bepodavoduwubimu.pdfIn PDF document text
    • http://top1np.com/ckfinder/userfiles/files/luzezagunowijopuxujuxe.pdfIn PDF document text
    • https://promptcorporate.com/ckeditor/ckfinder/userfiles/files/fijimomukoluwovolun.pdfIn PDF document text
    • http://ketphatthinh.vn/upload/files/melulujexozidalumofanog.pdfIn PDF document text
    • https://abisspaandboutique.com/nbloom/fckuploads/file/tugawagomuke.pdfIn PDF document text
    • http://dealershop.es/camarasegovia/userfiles/file/52260965767.pdfIn PDF document text
    • http://autostyle-japan.com/js/upload/files/57643549096.pdfIn PDF document text
    • https://optical-axis.com/uploads/files/202109080516274902.pdfIn PDF document text
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137e3a0e3d23---zesag.pdfIn PDF document text
    • https://sacc-la-chaux-de-fonds.ch/fichiers/file/37149945968.pdfIn PDF document text
    • http://erainbowrealty.com/userfiles/file/sazujusar.pdfIn PDF document text
    • https://stephan-kratt.de/data/reiterhof/userfiles/file/2074069300.pdfIn PDF document text
    • http://sunrui-ti.com/d/files/72142644003.pdfIn PDF document text
    • https://laundrybyconrads.com/nbloom/fckuploads/file/jewizeguwizaw.pdfIn PDF document text
    • http://asztalosweb.hu/userfiles/file/15482523330.pdfIn PDF document text
    • https://jmtours.co/aym_image/files/demivuzubutero.pdfIn PDF document text
    • http://saraswatishikshamandir.com/singhania/downloads/file/57876454550.pdfIn PDF document text
    • https://gpuhub.net/wp-content/plugins/super-forms/uploads/php/files/dq59qlndfaoc7mbq0bs2bk2d8n/dewonaxozetolukoli.pdfIn 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://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_off0000c3f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3F8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dc0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC0A 16760 bytes
SHA-256: 2ba2b2fd7afe560f708d0ffc50e1f728b3ece1da327510fc09c04ef7cb79d2ca
font_02_sfnt_off0001080d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1080D 10524 bytes
SHA-256: b304bf98da867f91d19aa8a6d1a7f9bf091591d1ac6e8cedd6ef2160331a6386