Malicious PDF — malware analysis report

Static analysis result for SHA-256 5c83fa571bfae263…

MALICIOUS

PDF

93.0 KB Created: 2021-07-16 05:22:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 4a3d25552790ac385fb253311b8fa084 SHA-1: cea60b03b1da6ad86b9f46b0a674848f45e268d8 SHA-256: 5c83fa571bfae26348de44293fe7e02caa93382a927311eced5a28bfc3201d6f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF document was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It contains a link farm pointing to compromised WordPress upload storage and other disposable hosting, suggesting an attempt to redirect users to malicious sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, indicating it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

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
  • 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://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607a7c4943cab---55595533834.pdf In PDF document text
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/16072264a6b992---29425385313.pdfIn PDF document text
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160ac2e69ebec8---buvazeriv.pdfIn PDF document text
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/1a173260e6ac5d0171337c37abe0c713/wivozokenuvusebufu.pdfIn PDF document text
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/d30771a0d584776fc2dab114f93531b2/91981386659.pdfIn PDF document text
    • https://cvenhancer.com/wp-content/plugins/super-forms/uploads/php/files/7121c571055977f6c21ebf4529525c90/wezizisazafos.pdfIn PDF document text
    • http://tachikawa-derma.biz/ckfinder/userfiles/files/gilis.pdfIn PDF document text
    • https://dmvassociates.com/wp-content/plugins/super-forms/uploads/php/files/a6a6c2a5fa1b1c16e1e48e762128fcc1/wonafesobe.pdfIn PDF document text
    • https://baxsporthorses.nl/userfiles/file/35384073217.pdfIn PDF document text
    • http://amctop.com/board_data/editor_img/file/202105211018.pdfIn PDF document text
    • http://jullien38.com/ressource/site-image/files/vokufoj.pdfIn PDF document text
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/160d5118974d7e---demutakerobapubuwuvew.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/qqic5hi0u08nsqk77tmbirufm4/82507363951.pdfIn PDF document text
    • http://studiosantese.eu/userfiles/files/penifulowolusuviworufavev.pdfIn PDF document text
    • https://deniz-sogutma.org/img/userfiles/file/25512497845.pdfIn PDF document text
    • https://www.havanasalsa-dance-tours.com/wp-content/plugins/super-forms/uploads/php/files/786883a314700c4a3006655652d28879/86675494944.pdfIn PDF document text
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/160c0d98dd3da8---27617574025.pdfIn PDF document text
    • http://c2mag.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ee11085cd6---zotelafikapujat.pdfIn PDF document text
    • http://countrysquirefoods.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607919152da54---fefuwujevo.pdfIn PDF document text
    • http://timatey.kz/wp-content/plugins/super-forms/uploads/php/files/5gn267jfs8q9g5jeqqdoq06pu7/64878612067.pdfIn PDF document text
    • http://barudan.hk/UploadFile/file/20210624064523339.pdfIn PDF document text
    • https://handinhand-daycare.com/ckfinder/userfiles/files/8160680744.pdfIn PDF document text
    • http://esistore.be/userfiles/file/83344252453.pdfIn PDF document text
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/47be68048d420bafe42a4029ac941f1a/zitifirozo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=the+construction+of+houses+5th+edition+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_off00010652.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10652 18072 bytes
SHA-256: 02d0c91f6b536e53124016d3d9f735ec5c44adf1bcdc52b5e6a3f48ce1d31ebf
font_01_sfnt_off00013631.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13631 10704 bytes
SHA-256: fdd8d0c1ba11de366d525f62c8887509578f2a4339089c55f1fa8c54527f054a
font_02_sfnt_off00014ebe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14EBE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

Open this report in the interactive analyzer, or submit your own file for analysis.