Malicious PDF — malware analysis report

Static analysis result for SHA-256 57a857224c411450…

MALICIOUS

PDF

71.9 KB Created: 2021-09-19 03:05:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 511810eb7901f0449ccb4eef106fceee SHA-1: 300a18d34592d4b77c8967e4fa4c19c8dc22b781 SHA-256: 57a857224c411450e4fa43987041e2b8efb9ed0decfbe05518f881467f77a4c9
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a ML classifier and ClamAV, indicating it is likely a phishing or malware distribution lure. The presence of numerous external URIs, many pointing to compromised CMS uploads or disposable hosting, suggests a link farm designed to redirect users to malicious content. No scripts were extracted, but the PDF structure and URL patterns are indicative of a phishing or malware delivery attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://kryotherapie.net/neu/userfiles/file/xaniwezuzoxokadupade.pdf In PDF document text
    • http://travelport.pl/userfiles/file/tijedulizalub.pdfIn PDF document text
    • https://dtd.com.pk/ckfinder/userfiles/files/wosomibujeno.pdfIn PDF document text
    • http://vstarmp.cn/upload/files/20210916_071427.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16139f9a1e9a99---52617509477.pdfIn PDF document text
    • https://jnnjhansi.com/userfiles/file/bafolagadorurerogasup.pdfIn PDF document text
    • https://bengalroys.com/ckfinder/userfiles/files/wunukoridakut.pdfIn PDF document text
    • https://prospr.fr/ckfinder/userfiles/files/takoredofut.pdfIn PDF document text
    • http://imobilestore.de/userfiles/file/vagazuwofilijo.pdfIn PDF document text
    • https://drinkpoint.com/uploads/files/taronogasimisefovezewu.pdfIn PDF document text
    • https://teater77.nl/userfiles/file/wurisuwuzulobabexifinegim.pdfIn PDF document text
    • https://asesoriagade.com/app/webroot/files/files/62510263611.pdfIn PDF document text
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/c93c2b9d9547c424dbbc3e0ce13f25df/kosekufawatiruw.pdfIn PDF document text
    • http://www.cpiequipos.com/assets/images/user_files/files/7116128827.pdfIn PDF document text
    • http://pwmtqatar.net/userfiles/file/wafafegimubedarakefakow.pdfIn PDF document text
    • http://pelejas.com/IMAGENS/CKFINDER/files/donurebukexenuvonog.pdfIn PDF document text
    • http://czechdidgeridoo.com/admin/upload/file/siwukipevuv.pdfIn PDF document text
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/j8k7ipjn8eodctvm8g7d79nc5p/samezavowa.pdfIn PDF document text
    • http://videocycling.info/files/file/xajasu.pdfIn PDF document text
    • http://leoclubmarsala.it/userfiles/files/zagimapomi.pdfIn PDF document text
    • http://vinhosnorte.com/images/files/keguraxewidaridifu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=25k+budget+phone+bdPDF 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_off0000b4ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4BA 17868 bytes
SHA-256: 99df00a1896cef30f816427493cf2a21a95ad6d75c7771a8ea9115ea88e5f0a6
font_01_sfnt_off0000e305.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE305 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fb1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB1C 10592 bytes
SHA-256: 3cb1f50aa41e8b983b4bae49539ed302a5f51ae7c9f4ef75e7ea7f31a89ba1fe