Malicious PDF — malware analysis report

Static analysis result for SHA-256 8439bfeb34a4d041…

MALICIOUS

PDF

92.5 KB Created: 2021-09-22 19:45:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 610c8ffc69d24bc3f52eba9e40624a0a SHA-1: fc99caa0d4e625ade9459eb74e231b3740a72ef0 SHA-256: 8439bfeb34a4d0411220479e89c1a2cee55db79c629cd8468f1a118a2c1367c7
156 Risk Score

Malware Insights

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

This PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to potentially compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. The presence of external URIs and a link farm indicates an attempt to lead the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9969

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 http://manuale.aziendasulweb.it/userfiles/files/9298389432.pdf In PDF document text
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16145ce7629bac---62136835151.pdfIn PDF document text
    • http://custom-mugs-factory.com/uploadfile/files/97808599935.pdfIn PDF document text
    • http://hugslock.com/app/webroot/img/files/48945280669.pdfIn PDF document text
    • http://thanhnhomdinhhinh.net/uploads/files/74170839468.pdfIn PDF document text
    • https://doanhnghiepvietnam.niengiamdoanhnghiep.vn/img_duhoc/files/pazuduruviwatix.pdfIn PDF document text
    • http://khocabien.com/uploads/files/mixuzawa.pdfIn PDF document text
    • https://mabuksusu.com/contents/files/26078724143.pdfIn PDF document text
    • http://rc-modeller.se/images/file///xunupo.pdfIn PDF document text
    • http://hibertek.com/image/files/20210906_111715.pdfIn PDF document text
    • https://alcoquimicos.com/ckfinder/userfiles/files/kepizawidev.pdfIn PDF document text
    • https://chilegastronomia.cl/uploads/userfiles/files/baxofabizibepuda.pdfIn PDF document text
    • http://milcontabil.com.br/wp-content/plugins/super-forms/uploads/php/files/ntk7e62lvvp20fd8skrmhm1pm2/36067107706.pdfIn PDF document text
    • http://huonglonghotel.com/uploads/image/files/sevarasovuvevunolozepena.pdfIn PDF document text
    • http://studiomilano.eu/userfiles/files/vebotojivafilotisirexiwo.pdfIn PDF document text
    • https://voicelux.ru/wp-content/plugins/super-forms/uploads/php/files/39467530dc5971e33caacff96f1e279f/9754663594.pdfIn PDF document text
    • http://beming.com/ressource/site-image/files/nekeluvaf.pdfIn PDF document text
    • http://teleinwestor.com/userfiles/file/tetunarugudodafasusumi.pdfIn PDF document text
    • http://dambi.pl/userfiles/file/46213204946.pdfIn PDF document text
    • http://redskap.ru/userfiles/file/gomazivilitorevit.pdfIn PDF document text
    • http://mathcountsoutreach.org/userfiles/file/31974765445.pdfIn PDF document text
    • http://vip-cond.ru/userfiles/file/60909853806.pdfIn PDF document text
    • http://reclameindex.nl/images/uploads/tewak.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=smurf+village+offlinePDF 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_off00010447.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10447 10532 bytes
SHA-256: c846b72d5e8206aaba3301105e56c1d4e031018cc48d9b787b3c0d41f3b75b34
font_01_sfnt_off00011c3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C3D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001344f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1344F 18368 bytes
SHA-256: f775db16f5e6f0df5b2f9fad1b8ea6c4e4de4052a6fc6a8d83a33e7a83e4e5bc