Malicious PDF — malware analysis report

Static analysis result for SHA-256 21cf8dafb62fb828…

MALICIOUS

PDF

78.4 KB Created: 2021-09-08 05:00:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 4745dfadce80129ddf816482babd3cc7 SHA-1: 2f4040a888e263b9fca97d0dc40d5065c2926bdb SHA-256: 21cf8dafb62fb828075ef4dab5703d321f51738025e3dba4a69172b9ff570187
154 Risk Score

Malware Insights

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

This PDF file was flagged by ML classifiers and ClamAV as malicious, indicating it likely exploits PDF vulnerabilities or contains malicious content. The heuristics reveal it functions as a link farm, pointing to numerous compromised CMS upload directories and disposable hosting sites, suggesting an attempt to distribute phishing content or second-stage malware. While no scripts were explicitly extracted, the nature of the links and the PDF format itself implies potential for embedded JavaScript execution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6236

Heuristics 5

  • 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
  • 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://cw-cut.com/uploads/file/xizowegirifutevajisu.pdf In PDF document text
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/1608ae27b3b2b6---80757596220.pdfIn PDF document text
    • http://zaun-produzent.de/userfiles/file/80963816630.pdfIn PDF document text
    • http://henskeschildersbedrijf.nl/upload/wikobagakuxapowikofuli.pdfIn PDF document text
    • http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/1gpgfvgf6pfb1a6a6v1r8nktsn/74458955329.pdfIn PDF document text
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cfd24c673d4---30108755559.pdfIn PDF document text
    • http://fotocaroli.it/userfiles/files/47829806647.pdfIn PDF document text
    • https://rajatotogroup3.com/contents/files/97025971705.pdfIn PDF document text
    • http://donateagift.eu/userfiles/file/buwivosadagofunefop.pdfIn PDF document text
    • http://taskentcompany.com/userfiles/file/molejimupe.pdfIn PDF document text
    • http://bergepkolcsonzo.hu/userfiles/file/zibijobofopiloniliku.pdfIn PDF document text
    • https://healthcareadvisorsgroup.com/wp-content/plugins/super-forms/uploads/php/files/83ifukr7jaes7i6r8ro4imdv91/73029094112.pdfIn PDF document text
    • http://hissekurban.com/resimler/files/75063466908.pdfIn PDF document text
    • http://www.orarestauratorisaf.it/wp-content/plugins/formcraft/file-upload/server/content/files/16087656b6428e---lebadalisogasufubogas.pdfIn PDF document text
    • http://www.cerathai.com/image/upload/File/gavupejavudefo.pdfIn PDF document text
    • http://waypl.pl/upload/File/lomosematovaf.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/3s6582uaipie0u1hfbf13skpn0/64277898671.pdfIn PDF document text
    • http://golden-candies.ru/webroot/files/files/xugeveriresoladujeretu.pdfIn PDF document text
    • https://law.myvzl.com/wp-content/plugins/super-forms/uploads/php/files/7cbtkjru29te3etc7tu6dp138n/bivowox.pdfIn PDF document text
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/16133feb8bb754---94662922899.pdfIn PDF document text
    • http://theofficeplus.com/userfiles/file/tiwoxu.pdfIn PDF document text
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609fbbf81a22d---suwexonosuratapibebe.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/160741044a20ae---dusebupup.pdfIn PDF document text
    • http://brilspa.ro/userfiles/file///kimemaretobugaki.pdfIn PDF document text
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/6e01c0eab1281668d78efa1428d4f97b/botogegifokavuwamupijedom.pdfIn PDF document text
    • http://jarosi.hu/files/file/13512461820.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=skeleton+worksheet+kindergartenPDF link annotation
    • 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_off0000dbe0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBE0 10780 bytes
SHA-256: 625859e839c42fe347b3435486b74f4db93f27448be78952f6c7721832b0ff91
font_01_sfnt_off0000f47a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF47A 18240 bytes
SHA-256: 5eb0d739e2460c9b958c2a47da5223fc6947d44c552ebb33f784011307abd989
font_02_sfnt_off000123fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123FB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1