Malicious PDF — malware analysis report

Static analysis result for SHA-256 8556f312d3f84879…

MALICIOUS

PDF

86.2 KB Created: 2021-09-12 19:50:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 103038c11d980113809adef03ce4d199 SHA-1: 702652c84f78cfe8311fc9b62ce7a0edb6051633 SHA-256: 8556f312d3f8487991fda621b5c8edfcca9bb017e5a1941f230a17514d8952a6
126 Risk Score

Malware Insights

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

The sample was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. The PDF contains numerous embedded URLs, many of which point to domains that appear to be part of a link farm, suggesting an attempt to redirect users to malicious content. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM specifically identifies this pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://jogamiskolc.hu/ckfinder/userfiles/files/16446225106.pdf In PDF document text
    • https://merohamro.com/ckfinder/userfiles/files/ludofusozubipore.pdfIn PDF document text
    • https://designclarf.it/file/83127357983.pdfIn PDF document text
    • http://ikra-ekb.ru/files/fckeditor/file/kakijuk.pdfIn PDF document text
    • http://www.kroonzuivel.nl/ckfinder/userfiles/files/17337667700.pdfIn PDF document text
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161396e575534e---desanokexoravaser.pdfIn PDF document text
    • https://cncunse.com/d/files/71826916686.pdfIn PDF document text
    • http://dungcumaymoc.com/Images_upload/files/41296051317.pdfIn PDF document text
    • http://cukorbetegshop.hu/files/77785067535.pdfIn PDF document text
    • http://kuresi-kaitori.com/upload/content_pic/files/miwifimelivuve.pdfIn PDF document text
    • https://www.shipgo17.com/plugin/ckeditor/ckfinder/userfiles/files/sugamiwexenuruxusi.pdfIn PDF document text
    • http://namadagaskare.ru/ckfinder/userfiles/files/66033964945.pdfIn PDF document text
    • https://traveletrust.com/basefile/traveletrustcom/files/xawam.pdfIn PDF document text
    • http://staractivecollection.com/resimler/site/files/wokiledukuvozuwor.pdfIn PDF document text
    • http://razaviota.ir/basefile/razaviotair/files/41411928154.pdfIn PDF document text
    • https://livre-d-art.com/ckfinder/userfiles/files/46051875490.pdfIn PDF document text
    • http://atek-ent.com/upload/file/javonafizapewotewutaju.pdfIn PDF document text
    • https://digireg.es/upload/58783482622.pdfIn PDF document text
    • https://www.shropshirefurniture.co.uk/admin/ckfinder/userfiles/files/zemug.pdfIn PDF document text
    • http://huspanda.com/data/ckfinder/files/fuvenosowopovini.pdfIn PDF document text
    • http://surmounttravel.com/userfiles/files/genanu.pdfIn PDF document text
    • https://pelicanfinancialnetwork.net/ckfinder/userfiles/files/lunuforodupajomifutomew.pdfIn PDF document text
    • http://frankslawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/33498994404.pdfIn PDF document text
    • https://specialgarden.ro/userfiles/file/45288494890.pdfIn PDF document text
    • http://daindnc.com/fckeditor/userfiles/file/ruzegosumakegum.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=how+to+factory+reset+a+tablet+that+is+lockedPDF 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_off0000e94e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE94E 18380 bytes
SHA-256: 0c70788375228926d778c4c32b937aad451d69857fb75bab86a793df355eb388
font_01_sfnt_off000118e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118E6 10892 bytes
SHA-256: 1ba89da3821656aea02e7418cf62143fbe4a59176edce57ceef2ecbd149eb280
font_02_sfnt_off0001324c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1324C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1