Malicious PDF — malware analysis report

Static analysis result for SHA-256 afde8b604a9c8f1f…

MALICIOUS

PDF

82.8 KB Created: 2021-09-23 05:45:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 1cee10c26ba6ef2d156c65750b3bba06 SHA-1: e4f0c92c4ede2865b7078656e0d6d959dfccce4e SHA-256: afde8b604a9c8f1feff791a9199e76f3064de026231a743ad7845744ecdcb01a
96 Risk Score

Malware Insights

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

The PDF contains a link farm with 32 URLs, many pointing to compromised CMS uploads and disposable hosting, indicating a phishing or redirection attempt. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent. No scripts were extracted, but the structure and URL distribution suggest a malicious document designed to lead users to external, potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 https://nikken-engineer.jp/export/sd205/www/jp/r/e/gmoserver/8/6/sd0748886/nikken-engineer.jp/fckeditor/upload/file/vasizubovumaraxodafeb.pdf In PDF document text
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613686e0f1192---29250589628.pdfIn PDF document text
    • http://salonorganica.ru/upload/files/wumanewufumowuxaxokowopul.pdfIn PDF document text
    • http://wirtrauenuns.ch/images/file/zisototivuzidunefupebubi.pdfIn PDF document text
    • http://thietbikhachsanvinhhung1.com/upload/files/80077288476.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/16147615a27a39---48888715551.pdfIn PDF document text
    • http://www.s4b.nl/upload/files/rimuvuxu.pdfIn PDF document text
    • http://md-servicios.com/userfiles/file/lisurelekipavobazivefatab.pdfIn PDF document text
    • https://biocoils.com/img/file/23058852241.pdfIn PDF document text
    • https://bbox.ru/images/shared/file/pifovapupodixipitulilux.pdfIn PDF document text
    • https://hondamienbac.vn/userfiles/file/kiwekafifurememusab.pdfIn PDF document text
    • http://bertrandetgastineaudesigners.fr/userfiles/file/22201937532.pdfIn PDF document text
    • http://styrexon.cz/userfiles/file/50448746557.pdfIn PDF document text
    • https://www.iieng.org/editor/ckfinder/userfiles/files/meradaxilaxa.pdfIn PDF document text
    • https://hantverkarenisandby.se/UserFiles/files/zeluzeraruvofefuka.pdfIn PDF document text
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/c739a03d0a493e9fafc83efb10069e05/79842345828.pdfIn PDF document text
    • http://baocaosuhoatoc.com/luutru/files/49060754381.pdfIn PDF document text
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/161337a21870cf---22901780264.pdfIn PDF document text
    • http://leton.pl/userfiles/file/17697165112.pdfIn PDF document text
    • http://usagimatur.com/files/others/50784403477.pdfIn PDF document text
    • http://dlzj.net/upload/files/20210919122211583537.pdfIn PDF document text
    • http://twinmd.ru/userfiles/file/47243354905.pdfIn PDF document text
    • https://perfecthospitals.org/FCKeditor/file/lekesom.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=japan+vpn+apkPDF 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_off0000e225.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE225 9640 bytes
SHA-256: 72852a9845f5ed4dc90099999ac16ed34bcb82e00a6645a7dc20c1674b87df0b
font_01_sfnt_off0000f71e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF71E 17888 bytes
SHA-256: cd9382fe6d72c40368186f281a71d5e63cd5c7d4c0e44c1df6491c33da80babc
font_02_sfnt_off000125c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125C8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1