Malicious PDF — malware analysis report

Static analysis result for SHA-256 5ef1b00cf148b564…

MALICIOUS

PDF

86.1 KB Created: 2021-09-02 04:14:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 851d76717c4b746ccb8fefe6a02ae687 SHA-1: db854bafb6cb871ae3d8ea46d0a9826c03f6a31b SHA-256: 5ef1b00cf148b56468761ad06f618117d59b776c7ffcf92de7afd5137eab9c2c
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL structure and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://esipro.lu/userfiles/file/raluxi.pdf In PDF document text
    • https://www.indee-r.fr/wp-content/plugins/super-forms/uploads/php/files/86fbf4075759bb265fe8db7e4ce7ed17/64120716508.pdfIn PDF document text
    • https://strategieb2b.com/userfiles/file/23223693544.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/160f8de0660575---17588887075.pdfIn PDF document text
    • https://brickzoo.it/file/vifax.pdfIn PDF document text
    • http://hindel-relax.ch/ckfinder/userfiles/files/fijizoliguxiriniwemuwugun.pdfIn PDF document text
    • http://www.mecateengenharia.com.br/ckfinder/userfiles/files/fapixug.pdfIn PDF document text
    • http://stlukesmn.org/clients/17773/File/82368427333.pdfIn PDF document text
    • https://a2designbg.com/userfiles/file/80151254864.pdfIn PDF document text
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606f13540c706---95175629265.pdfIn PDF document text
    • https://www.taxiserviceh24.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d329ad06f8---roxomevuxexise.pdfIn PDF document text
    • https://regeneracion-capilar.com/wp-content/plugins/super-forms/uploads/php/files/df725c5c0b952e3ce8dcd6edf60ddad5/dikonorija.pdfIn PDF document text
    • http://saharun.org/uploads/ckfinder/userfiles/files/21330482288.pdfIn PDF document text
    • https://grandegroup.net/files/zukufabote.pdfIn PDF document text
    • http://aaaexpressheating.com/userfiles/file/texuvinifubu.pdfIn PDF document text
    • http://cupta.org/userfiles/files/20210721155656.pdfIn PDF document text
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/8735e473c1e779b920e6da8cc54a7e98/73486391958.pdfIn PDF document text
    • http://apexibd.com/uploads/fck_uploads/file/47603987335.pdfIn PDF document text
    • http://hotstamping.pl/files/file/23918458496.pdfIn PDF document text
    • http://muzycznescyzoryki.pl/userfiles/file/70163508555.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=ricky+gervais+christopher+guestPDF 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_off0000e8e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8E3 18288 bytes
SHA-256: f58c5bcd0b30cff9e176197c2eb6d4631e44f4f7ed2660a7ac786d96b7a92656
font_01_sfnt_off00011886.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11886 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001309d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1309D 10920 bytes
SHA-256: 5f26133d831edbd3804111faef346d09007216d82fcc08d92038cee94c772cda