Malicious PDF — malware analysis report

Static analysis result for SHA-256 7b83d87c6e459697…

MALICIOUS

PDF

73.4 KB Created: 2021-09-30 12:45:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 68c5816b3cbac1d7ba4570f31faa447a SHA-1: 83fdccae549cc20b61eebf67459b348fbfce068e SHA-256: 7b83d87c6e4596979677e6eff52a00d119c6608f81ff6a8e49b160ca6cca9c64
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection for 'Pdf.Phishing.Trojan' and an ML classifier indicating maliciousness. The presence of numerous external URIs, many pointing to PDF files on distinct hosts, suggests a link farm designed to redirect users. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically identifies this pattern. No scripts were extracted, but the overall structure and heuristic firings strongly indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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 http://singer-island-condos.com/userfiles/files/wepitipibi.pdf In PDF document text
    • http://alcantara.cz/data/file/wiwulazujiguz.pdfIn PDF document text
    • https://saintarseny.ca/sites/saintarseny.ca/files/file/95588662630.pdfIn PDF document text
    • https://aparcaderoshaddaichile.cl/uploads/images/files/vuterali.pdfIn PDF document text
    • http://itcck.org/upload/editor/file/32578667122.pdfIn PDF document text
    • http://inbiosa.eu/static/cfiles/files/gevilapafex.pdfIn PDF document text
    • http://union.travel/ckfinder/userfiles/files/gepefulakogad.pdfIn PDF document text
    • http://refpecsbelvaros.hu/kepek/files/69512957251.pdfIn PDF document text
    • http://lotusromeo.fr/app/webroot/files/userfiles/files/purikenofuwiporumeb.pdfIn PDF document text
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f145d21bc0---filuwufogalozo.pdfIn PDF document text
    • https://rijst.nu/userfiles/file/dalagow.pdfIn PDF document text
    • http://arunimaflavours.com/userfiles/file/16112067767.pdfIn PDF document text
    • https://giraffeng.net/infodaily/gen-ckfinder/userfiles/files/setamelilimogewuvel.pdfIn PDF document text
    • https://vadihosting.com/calisma2/files/uploads/54287411722.pdfIn PDF document text
    • http://commissioncollectionlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/nilulexo.pdfIn PDF document text
    • https://brianspradlin.com/userfiles/file/sowaper.pdfIn PDF document text
    • http://tiga.co.th/ckfinder/userfiles/files/18439616333.pdfIn PDF document text
    • http://saovietgroup.com/upload/FCK/file/mivagerejokuturev.pdfIn PDF document text
    • http://daotaoyduoc.org/wp-content/plugins/super-forms/uploads/php/files/1c83cc1b65aac3697a575dd182b7e014/41631008037.pdfIn PDF document text
    • https://netwindowvn.com/uploads/userfiles/file/97837430086.pdfIn PDF document text
    • https://tanhoaphat.vn/userfiles/file/76780675342.pdfIn PDF document text
    • http://aiswaryamatrimonials.com/fck_uploads/file/bagutevixafadoluvu.pdfIn PDF document text
    • http://myrbacken.se/login/ckfinder/userfiles/files/tujasogowupoxugedivuneke.pdfIn PDF document text
    • http://daithanhnam.com/upload/files/85140014971.pdfIn PDF document text
    • http://rayer.cn/d/files/wiregajagekefetofira.pdfIn PDF document text
    • https://ecodiagnost.com/ckfinder/userfiles/files/belevakapixaxavemulijefi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=play+store+install+free+firePDF 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_off0000b807.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB807 10324 bytes
SHA-256: 77b17506ff747c5d1b13583352e4b47b200b000dd7820fb1518afa310d3dbe44
font_01_sfnt_off0000cf7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF7F 18780 bytes
SHA-256: a0a534500d153cdfd37bf580e4d00fa02e9c20712858bb27888ec185cb2f61db
font_02_sfnt_off00010029.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10029 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1