Malicious PDF — malware analysis report

Static analysis result for SHA-256 efe521c4c45d686b…

MALICIOUS

PDF

82.0 KB Created: 2021-09-13 15:56:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 4a4c255648e9b3a78e9365ff87c57d99 SHA-1: 771d2b5d51b02fdde4f12a2a6d7035ad8568c9b9 SHA-256: efe521c4c45d686bea0db4f5c5cdf38026d29c9af14b35080d2594cc0c0f5643
134 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript, a common technique for executing malicious code within documents. The heuristic 'ML_NYX_PDF_MALICIOUS' and ClamAV detection strongly indicate malicious intent. The embedded JavaScript likely facilitates the redirection to external URLs, as suggested by the 'PDF_URI' and 'EMBEDDED_URL' findings, which are often used in phishing campaigns or to download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9894

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
  • 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 http://feg.vn/uploads/files/24242711692.pdf In PDF document text
    • http://ezclasssites.com/var/wwww/dev-ezclasssites-com/data/files/fasotebabezunox.pdfIn PDF document text
    • http://solee56.com/ckfinder/userfiles/files/20787889415.pdfIn PDF document text
    • http://hindustanadvancedsolution.com/t/tutorfirm/uploads/ck/files/zufodinukexi.pdfIn PDF document text
    • https://alarrabnews.com/images/content/content/file/xawisoz.pdfIn PDF document text
    • https://linhquan-group.com/upload/ck/files/26639866708.pdfIn PDF document text
    • https://kapokcmassage.com/uploads/files/202109011836257500.pdfIn PDF document text
    • https://r4binsh4h9-att.com/contents/files/kivokajemiziwofaseguvi.pdfIn PDF document text
    • http://yuli-china.ru/d/files/20561142125.pdfIn PDF document text
    • https://aftaplan.com/works/peepsparty/html/upload_files/file/95375522044.pdfIn PDF document text
    • http://radissonhoteltraining.com/userfiles/file/poboxumelutaxumi.pdfIn PDF document text
    • http://abwingsmd.com/uploads/files/91795768492.pdfIn PDF document text
    • http://www.phuongdonggolf.vn/app/webroot/uploads/files/memawemurifuses.pdfIn PDF document text
    • https://rdw-wolf.de/backend/ckfinder/userfiles/files/kokiwudafeda.pdfIn PDF document text
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613ef1d12bec3---10482893515.pdfIn PDF document text
    • http://thegioioto.store/upload/files/gutovexibebojoronolepe.pdfIn PDF document text
    • http://phongkhamthienhoa.vn/images/files/kovovep.pdfIn PDF document text
    • http://hcbarrett.com/user_area/file/71068570821.pdfIn PDF document text
    • http://skisun.it/userfiles/files/12559065849.pdfIn PDF document text
    • http://amongelite.com/ci/userfiles/files/68877796015.pdfIn PDF document text
    • http://carneiro-sa.pnh.pt/js/ckfinder/userfiles/files/wedefunawutosow.pdfIn PDF document text
    • https://digireg.es/upload/wataregulage.pdfIn PDF document text
    • http://hasicimosnov.cz/foto/Image/file/xuzararusibatuzorimak.pdfIn PDF document text
    • https://zazilha.com.mx/wp-content/plugins/super-forms/uploads/php/files/8cd192fb4c0424e22f5741b63a56ad58/xujur.pdfIn PDF document text
    • http://runhouchem.com/upload/files/zawiv.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=flags+of+our+fathers+pdfPDF 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_off0000da6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA6A 10660 bytes
SHA-256: 23c5b231bf640724ba4a9f871549d0cbab00823dd09d5c773e3a906f2ff1e4e9
font_01_sfnt_off0000f2c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2C7 18252 bytes
SHA-256: e9a42e219d70919b9b780dc5d2762f7aaee27d1d0be961c562e72520f5adf15f
font_02_sfnt_off00012278.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12278 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1