Malicious PDF — malware analysis report

Static analysis result for SHA-256 df36259da33689d8…

MALICIOUS

PDF

83.5 KB Created: 2021-09-11 08:28:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 1b0c5ab36ce854302b6213039431c45a SHA-1: f9ea8c52bc355a00a6c7247bab6e52fced765740 SHA-256: df36259da33689d8561d1be64766d2191a1af81c21dcc4a5e07676e5253508ab
126 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating it is likely a phishing or trojan delivery mechanism. The PDF contains numerous embedded URLs pointing to various domains, suggesting a link farm or redirection strategy. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly indicates the purpose is to manipulate search engine results or host a large number of potentially malicious files.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

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://euchebnici.com/img/file/naxebusinevigafibitox.pdf In PDF document text
    • http://tasteofruraleurope.eu/upload/File/kakonom.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a3392d4d35---75433744437.pdfIn PDF document text
    • https://budapestpainter.hu/ckfinder/userfiles/files/matakukir.pdfIn PDF document text
    • http://westfallassociates.com/documents/file/tojuvutuvil.pdfIn PDF document text
    • http://titadoorbinhduong.com/upload/files/62166310865.pdfIn PDF document text
    • http://worldsocialistpartyindia.org/ckfinder/userfiles/files/linasakesure.pdfIn PDF document text
    • http://kojeneckezbozi.eu/userfiles/file/jebigupoduwabomires.pdfIn PDF document text
    • http://volareinmongolfiera.it/userfiles/files/39797456186.pdfIn PDF document text
    • https://deepex.hu/hirek/files/57327909495.pdfIn PDF document text
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1612fc4a592318---53820331911.pdfIn PDF document text
    • https://vargyasnekonyveles.hu/kepek/other/file/40133519808.pdfIn PDF document text
    • https://divinenine.net/userfiles/file/baduwisinexewisetubukas.pdfIn PDF document text
    • http://dsacare.com/admin/uploads/file/27092485411.pdfIn PDF document text
    • https://esofagopisa.it/userfiles/file/bubino.pdfIn PDF document text
    • http://osteriadelcampanile.com/userfiles/files/telopulomotajefopep.pdfIn PDF document text
    • http://circolonauticofavignana.it/userfiles/files/15396354394.pdfIn PDF document text
    • http://kxqcgs.net/filespath/files/20210908090531.pdfIn PDF document text
    • http://thegioixedap.net/upload/files/kazekonixirozevasusanov.pdfIn PDF document text
    • http://www.phuongdonggolf.vn/app/webroot/uploads/files/zuruvokunexusimo.pdfIn PDF document text
    • https://portugaliaimagyarok.com/ckfinder/userfiles/files/zewakomapabamimej.pdfIn PDF document text
    • https://myagenda.myagenda.cz/pictures/editor/files/74381158655.pdfIn PDF document text
    • https://ixiu-23.com/uploads/files/202109060753327223.pdfIn PDF document text
    • http://huiking.cn/uploads/file/021745522138.pdfIn PDF document text
    • https://flyags.com/editorResources/file///11232147589.pdfIn PDF document text
    • https://legouic-peinture.fr/userfiles/file/33029926896.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=call+volume+low+androidPDF 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_off0000e0d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0D6 10424 bytes
SHA-256: abaf3e8bbdb008ed598dc729d38b144f0fc9702a4f333e9f17e505ed7b2873eb
font_01_sfnt_off0000f873.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF873 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011085.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11085 18416 bytes
SHA-256: e2e13ba8e29ee3b3519e437f2ed74fc22cb52f82bbdbfbdc1ec76cabdb26fae0