Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7582403deaec96c…

MALICIOUS

PDF

82.2 KB Created: 2021-09-03 18:31:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 346b5fa8bef26bd216f801eb7647b6f7 SHA-1: cdac26d59a8b2bf6f6ce1468251bf5a87a0aa82d SHA-256: a7582403deaec96c21503268125b31f51492cc234b1331d773e01b3ad1fc885c
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to compromised CMS uploads and disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The PDF structure and embedded links are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 https://xn--64-mlcufjjaii0l.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/d8c01557a90944e4798b2859038ece0c/rubatexik.pdf In PDF document text
    • https://appchecar.com/ckfinder/userfiles/files/pokitamafonenafasozaken.pdfIn PDF document text
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a39d650327c---naxefovabejapojozomu.pdfIn PDF document text
    • http://cuanhomkinhtoanthang.com/media/file/17840173326.pdfIn PDF document text
    • https://call-life.com/ckfinder/userfiles/files/binarufitagewekibakuwepo.pdfIn PDF document text
    • http://dnepropress.net/files/file/95008800165.pdfIn PDF document text
    • http://ros.by/ckfinder/userfiles/files/wetowejatif.pdfIn PDF document text
    • https://thesaddlebank.com/wp-content/plugins/super-forms/uploads/php/files/453k3eoohaq7j0uha5vknjh8ip/36659316747.pdfIn PDF document text
    • https://alfa-pechati.ru/wp-content/plugins/super-forms/uploads/php/files/3851103f42a86c9a8564fc8fbe1208a6/29265780818.pdfIn PDF document text
    • http://www.sempresaude.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a14c12e4714---92954097891.pdfIn PDF document text
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e48b842cd0---67002584043.pdfIn PDF document text
    • http://abcbyspu.net/ckfinder/images_store/files/37215504650.pdfIn PDF document text
    • https://arerp.kr/data/file///91791609675.pdfIn PDF document text
    • http://www.sospapa24.com/lib/ckfinder/imgupload/files/26750603307.pdfIn PDF document text
    • http://healthywithhart.com/res/file/9020358001.pdfIn PDF document text
    • http://slsnn.ru/content/files/bovudivasazurazorodosi.pdfIn PDF document text
    • https://soudurelauziere.com/upload/editor/file/15289568134.pdfIn PDF document text
    • https://olterus.net/contents//files/suvareperoj.pdfIn PDF document text
    • http://sakem.org/userfiles/files/bejukosevekoj.pdfIn PDF document text
    • http://suseefinance.com/userfiles/file/36921343146.pdfIn PDF document text
    • https://imotrading.com/images/userfiles/kojobomofovufoxijakida.pdfIn PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/liinem522kp4civm1qhgqifctq/jukonudaditoxab.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/304885ec5ea1c927c36ff5b16647a75b/30641572936.pdfIn PDF document text
    • https://giriconsultancy.com/content_files/files/50744835560.pdfIn PDF document text
    • http://accomplishtheimpossible.com/userfiles_ati/file/10118563852.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=answer+sheet+toeic+iig+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_off0000d307.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD307 10756 bytes
SHA-256: 98b1cf9a69c650820630eae8f2e5237fcc744b66c1903c9977654021d7fe9904
font_01_sfnt_off0000eb97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB97 21152 bytes
SHA-256: 800e2ed088cff960e2feb3ed39909bb55de992255331291958b005a7b2f7bcf4
font_02_sfnt_off0001234b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1234B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1