Malicious PDF — malware analysis report

Static analysis result for SHA-256 81756555ae5b15a9…

MALICIOUS

PDF

74.0 KB Created: 2021-05-10 05:45:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-04
MD5: 58167e78680b6c63068fcb8e58dc137b SHA-1: 556bb889e5c94b9a8ea9042c6029e8074dc6a942 SHA-256: 81756555ae5b15a94295222c67658406d009a101d188311e4714df9d9e02d824
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://leesman.com/wp-content/plugins/super-forms/uploads/php/files/503511ad12061ab0cd2c3bacfe02fc21/73582032935.pdf In PDF document text
    • https://www.nobleorthodontic.com/wp-content/plugins/super-forms/uploads/php/files/80a816270fc96cf2486689b2190418d8/kojedi.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b53cc9d39f---mamikukipesubedakiwor.pdfIn PDF document text
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160786df5bbe36---9925076336.pdfIn PDF document text
    • https://thehamptonsbloomington.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094448b6c2a5---tutasom.pdfIn PDF document text
    • http://agendatourvietnam.com/hinhanh/file/24918029974.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/tv8fam65cfn2hl184hn32mq7h3/texarobalidupesofak.pdfIn PDF document text
    • https://iguanapools.com.au/wp-content/plugins/super-forms/uploads/php/files/hjdspsud3kp2p31md2aun35h94/35007264353.pdfIn PDF document text
    • https://hiampelectric.com/wp-content/plugins/super-forms/uploads/php/files/e07820906d894f8caf34ceef8774f24d/4340404311.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607f4224d82ce---webivalonewuxov.pdfIn PDF document text
    • http://ackerviewguesthouse.com/userfiles/file/78572527607.pdfIn PDF document text
    • http://dobryremont.pl/ebobas/portal/app/webroot/img/tmp/file/16205848723393.pdfIn PDF document text
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160749c27ee4a1---rovixovutabeloxefaborap.pdfIn PDF document text
    • https://calldidocta.com/wp-content/plugins/super-forms/uploads/php/files/e1fbacf5133685d239a997eb2246c9c8/85672300270.pdfIn PDF document text
    • http://thefutureofgolf.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16073fdb6c9e83---dipamobigafesib.pdfIn PDF document text
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/d1288f34e9d5624a1d2aa25650720f60/87394573862.pdfIn PDF document text
    • http://alliusie.com/userfiles/file/liremodubuwututilagewuwo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=google+sheets+if+or+statementsPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e80b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE80B 5212 bytes
SHA-256: 6efb56a27d5d26780ac9af22094647a7d640e4909e4d0e9c6fb0e2065b9616ab
font_01_sfnt_off0000f9a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9A1 9848 bytes
SHA-256: 5b8d0598753f197ea8c08831451f30ba0bf1519ddda926e6559003e0fb94d34e