Malicious PDF — malware analysis report

Static analysis result for SHA-256 6d8edc00d36db042…

MALICIOUS

PDF

73.1 KB Created: 2021-09-12 11:38:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: cffc419e0e5c354e6a8e4678888a433f SHA-1: 367dc3055079e1f70d42c54e067da407b772e9b3 SHA-256: 6d8edc00d36db04245d6d4552e16adc885bbb792c1b8410eb8f740a5e1739e5a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous URLs that form a link farm, with several pointing to compromised WordPress sites, suggesting a phishing or malware distribution scheme. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://catamma.ru/uplcv?utm_term=plane+geometry+book+pdf PDF link annotation
    • http://elliptical-trainers.ru/ckfinder/userfiles/files/rujok.pdfIn PDF document text
    • http://kelsenator.com/userimages/23834692021.pdfIn PDF document text
    • https://alshuka.ps/ckfinder/userfiles/files/xapikizubanapategikijiro.pdfIn PDF document text
    • https://maritime-models.com/userfiles/file/ruxege.pdfIn PDF document text
    • http://madonnina.info/userfiles/files/22193778357.pdfIn PDF document text
    • http://balcimimarlik.com/resimler/files/jomosolilas.pdfIn PDF document text
    • http://tks-forever.com/upload/2021/09/01/file/jaburovaxikowekotuxiluf.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/161324eee13789---kokifojiditemakilirolug.pdfIn PDF document text
    • http://www.sarajevo-inn-grunewald.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137bc93c70b4---pumuzobup.pdfIn PDF document text
    • http://taxicityplus.ru/userfiles/file/zijuzivazogi.pdfIn PDF document text
    • http://kayapalinakliyat.net/file/zikow.pdfIn PDF document text
    • http://www.fotografoeventimilano.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613667810be1d---16659428694.pdfIn PDF document text
    • http://wdnederland.nl/file/37387375858.pdfIn PDF document text
    • http://kronikarp.pl/ckfinder/userfiles/files/6931334444.pdfIn PDF document text
    • http://msslink.ru/userfiles/files/diposapulufake.pdfIn PDF document text
    • https://dgaspcsm.ro/ckfinder/userfiles/files/17203479506.pdfIn PDF document text
    • https://przygodanaukrainie.pl/admin/ckfinder/userfiles/files/63180129390.pdfIn PDF document text
    • http://radissonhoteltraining.com/userfiles/file/28891409336.pdfIn PDF document text
    • http://harmonie-avion.fr/actualite/files/18591805087.pdfIn PDF document text
    • https://rireenfrance.com/images/upload/files/lisanapaluli.pdfIn PDF document text
    • http://pk.mo/userfiles/file/62179741381.pdfIn PDF document text
    • http://vpsystem.com/files/fck/pekogefixawafomar.pdfIn PDF document text
    • https://limsurdua.com/contents/files/23906735090.pdfIn PDF document text
    • http://decom.pro/admin/ckfinder/userfiles/files/larexevoji.pdfIn PDF document text
    • 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_off0000bcd4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBCD4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d4e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4E6 16000 bytes
SHA-256: f3516ec16e980866853ef3a1e1d93496e03a1949e3b75470f7cf2d54bdf9bd52
font_02_sfnt_off0000fdec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDEC 10928 bytes
SHA-256: 75bf4676826722e893fa394cf23a063a2de3d385e067dcefa9c450d7ef849cf9