Malicious PDF — malware analysis report

Static analysis result for SHA-256 3656598be1a28f5c…

MALICIOUS

PDF

80.3 KB Created: 2021-09-17 05:34:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: dfbd3ad1c170b1b548af5380e4a6140a SHA-1: db2fb897fcda8cbb93b5832dba6d871c9a4fb3a9 SHA-256: 3656598be1a28f5c5ba4981643e5a73122c62aa64e0b20d0ef5103992d0417db
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains embedded JavaScript and numerous external URIs, many of which point to PDF files on potentially disposable hosting, indicating a link farm. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, suggesting the document is part of a scheme to manipulate search engine results or distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://geerhannutpourreussir.be/docs/upload/files/26048979837.pdf In PDF document text
    • http://chrisdepanneservices.com/Sites/cds/files/mosupakepumezoliliba.pdfIn PDF document text
    • http://shiinamotors.com/js/upload/files/90206439082.pdfIn PDF document text
    • https://eccdc.org/application/webroot/userfiles/file/35618743875.pdfIn PDF document text
    • http://heatexchangersolution.com/upload_fck/file/2021-9-14/20210914041339512631.pdfIn PDF document text
    • https://magnanerie-cazilhac.com/userfiles/file/fekapezot.pdfIn PDF document text
    • https://abss.pt/userfiles/file/25987199632.pdfIn PDF document text
    • http://15881588.com/ckupload/files/ditowo.pdfIn PDF document text
    • http://studiolegaletrotta.eu/userfiles/files/vogakonewajuwowuwelemod.pdfIn PDF document text
    • http://mc-opony.pl/files/file/60591580873.pdfIn PDF document text
    • http://maybaobidinhdinh.com/upload/files/surejadagumapujon.pdfIn PDF document text
    • http://ceresasrl.it/userfiles/files/89892579728.pdfIn PDF document text
    • http://htk2.altrodesign.eu/ckfinder/userfiles/files/89696985961.pdfIn PDF document text
    • http://klgd.spokoino.ru/i/upload/files/61903554290.pdfIn PDF document text
    • https://rockyhotelsgroup.com/uploaded/files/16406050774.pdfIn PDF document text
    • http://radioevangilereal.com/assets/ckfinder/core/connector/php/uploads/files/bexuvatexivabi.pdfIn PDF document text
    • http://atut-biuro.com/uploaded/file/jexebulogi.pdfIn PDF document text
    • https://apotekatia.ba/fajlovi/foranipe.pdfIn PDF document text
    • http://vdgairconditioning.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16130e85969db8---76972448760.pdfIn PDF document text
    • http://braindevelopmentmaps-org.neurondevelopment.org/userfiles/files/84526280950.pdfIn PDF document text
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/g74a5np964q3ba6vg8335rdk94/91668921526.pdfIn PDF document text
    • http://lnianemarzenie.pl/userfiles/file/2422176104.pdfIn PDF document text
    • https://tadimtursu.com/image/files/zuwusa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=how+to+set+default+messaging+app+in+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_off0000d587.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD587 16908 bytes
SHA-256: 253758d23a665f13587f7a85afa8b913273b2f278fefa63303459159996bf857
font_01_sfnt_off00010183.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10183 11016 bytes
SHA-256: 9b2c976a596c664880a6377fb086967903780bcadc6323f2cb4c342d3f84ae92
font_02_sfnt_off00011ae9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AE9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1