Malicious PDF — malware analysis report

Static analysis result for SHA-256 83d757314be081a7…

MALICIOUS

PDF

79.8 KB Created: 2021-09-08 10:32:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: ab740431748cc5894d641f083ec0c76d SHA-1: a55edd667532c546caa8f31f81b0e113c52d4d9e SHA-256: 83d757314be081a7aa376f32553db1204993874eeac38a5fede61d7d9d578930
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised WordPress upload storage, suggesting it's designed to lure users to external sites. The presence of numerous unknown URLs reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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 http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160874990e4976---xopoxukexav.pdf In PDF document text
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aaf7eee0b8c---4073613093.pdfIn PDF document text
    • http://humboldthighclassof79.com/clients/1/19/19f040aad945c40a0acbd79abd3dc6cb/File/48329354104.pdfIn PDF document text
    • https://churchofgodinjamaica.org/app/webroot/files/19493305781.pdfIn PDF document text
    • https://nicemexico.net/wp-content/plugins/formcraft/file-upload/server/content/files/16093a832ca401---71316632067.pdfIn PDF document text
    • https://g3az.com/wp-content/plugins/formcraft/file-upload/server/content/files/16118bb028355c---magebubekewal.pdfIn PDF document text
    • https://www.leadercaravans.com.au/application/third_party/ckfinder/userfiles/files/zigukupivakomupijalaf.pdfIn PDF document text
    • https://suadienlanhhanoi.net/upload/files/17855162616.pdfIn PDF document text
    • http://www.parinet.fi/tiedostot/files/bokubukikunopunadaz.pdfIn PDF document text
    • http://epplast.com/files/file/tumakukupukenuzulifiberi.pdfIn PDF document text
    • https://powermailer.in/userfiles/file/penutulosigobarikimeme.pdfIn PDF document text
    • https://costumeworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077c6d87b4dd---kakaxezibawebupiruxerol.pdfIn PDF document text
    • http://henca.com/files/details/file/47877933616.pdfIn PDF document text
    • http://www.dadosefatos.net.br/wp-content/plugins/formcraft/file-upload/server/content/files/16097afa26dceb---19446564981.pdfIn PDF document text
    • https://turdv.ru/SITE/files/editor/file/vetelunot.pdfIn PDF document text
    • http://fred-robin.com/ckfinder/userfiles/files/43137473508.pdfIn PDF document text
    • https://almuhja.ps/ckfinder/userfiles/files/wuxesiziferugusor.pdfIn PDF document text
    • http://refta-bg.com/userfiles/file/rewasi.pdfIn PDF document text
    • http://www.alwaysflorida.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c3df0f41a62---jekesewesafejikizigagabik.pdfIn PDF document text
    • https://growyourmoney.in/userfiles/files/beketovenas.pdfIn PDF document text
    • https://djhelaly.com/wp-content/plugins/super-forms/uploads/php/files/2c5803ca71b190c74ce5df0ef6b3d80b/29789503784.pdfIn PDF document text
    • http://www.macrolepidoptera.hu/userfiles/files/58287248565.pdfIn PDF document text
    • https://burgas-remonti.com/userfiles/file/46018092572.pdfIn PDF document text
    • https://www.pfgpartners.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609a0caabd3ce---73300229100.pdfIn PDF document text
    • http://gojjang.com/uploads/files/21632088107.pdfIn PDF document text
    • http://www.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/160bdb3012c343---wifoxipijoxuvujasa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=grammar+practice+workbook+grade+12+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_off0000d244.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD244 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ea56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA56 17256 bytes
SHA-256: 882abc42e7dc355ce48bfbcfe3eb13c1256b7635438c2f1f54c42513d17af3de
font_02_sfnt_off0001172f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1172F 11176 bytes
SHA-256: 6330fb16f3c125ce7e362a24eafcd28cd5bcd89f0b8453e33bb87ccb1281fd02