Malicious PDF — malware analysis report

Static analysis result for SHA-256 e6e8b3cb075c93ce…

MALICIOUS

PDF

69.8 KB Created: 2021-09-28 14:01:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: a7e768486ec8ea3c6282449092e5d38d SHA-1: 544962a689de6e5b1af53d209d10cc0b6709bbba SHA-256: e6e8b3cb075c93ce27f78e1525a13ece9510055474fd16f9e98af3398dea07d7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier, with multiple heuristics indicating it functions as a link farm. The embedded URLs point to various domains, many of which appear to be compromised or disposable hosting, suggesting an attempt to obscure the ultimate destination. The presence of PDF-specific heuristics like 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly supports the link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://allytemp.ru/uplcv?utm_term=block+city+wars PDF link annotation
    • http://giorgimpianti.com/userfiles/file/jilosidoxopesipomu.pdfIn PDF document text
    • http://automsystem.com/UploadFile/file/20210905233634515.pdfIn PDF document text
    • http://swiftnb.com/ckfinder/userfiles/files/79351918576.pdfIn PDF document text
    • https://larrialdiak.es/files/galeria/files/gufilezufevidotugata.pdfIn PDF document text
    • http://dynamicyunnan.com/ckfinder/userfiles/files/nepasinotaxewosolumudu.pdfIn PDF document text
    • http://scandirent-new.ru/uploads/assets/file/gebewido.pdfIn PDF document text
    • http://diagonal.org.ar/wp-content/plugins/formcraft/file-upload/server/content/files/161452ced2db0a---85461655695.pdfIn PDF document text
    • http://bibrka-school.org.ua/ckfinder/userfiles/files/vujafokoxelafut.pdfIn PDF document text
    • https://leunamgroup.com/wp-content/plugins/super-forms/uploads/php/files/8a85f7078706c6ca84b438efd3eb9d26/83535766311.pdfIn PDF document text
    • http://apexibd.com/uploads/fck_uploads/file/melipudiro.pdfIn PDF document text
    • http://www.marcado.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161369ba697c95---34731585692.pdfIn PDF document text
    • https://costabravas.com/uploads/localidades/files/28014194882.pdfIn PDF document text
    • http://dd-eng.com/files/files/zibuvokifemolupenazifes.pdfIn PDF document text
    • http://www.gc-antey.ru/ckfinder/userfiles/files/tewev.pdfIn PDF document text
    • http://sgyscom.com/upload_fck/file/2021-9-26/20210926225735853375.pdfIn PDF document text
    • https://gulfsupremesa.com/ckfinder/userfiles/files/gikomol.pdfIn PDF document text
    • https://amatnieks.lv/pictures/image/55945591652.pdfIn PDF document text
    • http://supair-lux.hu/ckfinder/userfiles/files/letixutibejejotaka.pdfIn PDF document text
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1614cdbd06c608---52883268323.pdfIn PDF document text
    • http://cityclick.it/userfiles/files/nerawederiw.pdfIn PDF document text
    • http://www.hebrewforreadingcomprehension.com/content/47889715765.pdfIn PDF document text
    • https://sinarwaja.com/account/files/nenijimuwaruwudizufu.pdfIn PDF document text
    • https://holcom-solar.com/webroot/img/files/gofamemadavidiweposewa.pdfIn PDF document text
    • http://riviera.az/userfiles/file/15196371899.pdfIn PDF document text
    • http://fruitvita.com/files/files/95419323646.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_off0000b0fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0FB 16408 bytes
SHA-256: a69e7e73aee14410d9bcdf63749dc107f64402664b82000cb9abca23bdebd77c
font_01_sfnt_off0000daa4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAA4 10332 bytes
SHA-256: 686640066d1977f5964bd8a5a68c093ed53546dffa04dba20347b08d74d44401
font_02_sfnt_off0000f237.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF237 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1