Malicious PDF — malware analysis report

Static analysis result for SHA-256 2255ac7dd8971065…

MALICIOUS

PDF

69.3 KB Created: 2021-10-01 19:34:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 2114993a5fec44d5afc11b525d6b1fe8 SHA-1: 9e02d38a0814dc6c9bfd475df5f8f12a46606525 SHA-256: 2255ac7dd89710657ab98c5fbbe37a0ff2d07ecdc5fc16b8c1071d5125b3740f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm on disposable hosting, with numerous external URIs pointing to various domains. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool often used to create PDF documents from web content, further supporting the link farm hypothesis.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://infrive.ru/uplcv?utm_term=itunes+card+generator+2020 PDF link annotation
    • https://adproissy.emailingmanager.com/uploads/editor/file/lanujawerepuzig.pdfIn PDF document text
    • http://olgapolyakova.de/files/files/tupawavaruvasalul.pdfIn PDF document text
    • https://binarbaid.com/public_html/userfiles/file/rosapomix.pdfIn PDF document text
    • http://nhasachnguyenvancu.com/Images_upload/files/33773210829.pdfIn PDF document text
    • http://nurugelexport.com/ckfinder/userfiles/files/87598822040.pdfIn PDF document text
    • https://deesudcoolingtower.com/userfiles/file/netajuwitapilebebaxivag.pdfIn PDF document text
    • https://edouardweil.com/userfiles/file/wumorubovok.pdfIn PDF document text
    • http://liqaa-lb.com/files/userfiles/files/tivika.pdfIn PDF document text
    • http://language-coach.pl/uploads/files/25900763508.pdfIn PDF document text
    • http://jeanthompson.nl/ckfinder/userfiles/files/43220912766.pdfIn PDF document text
    • https://blugarden.eu/file/53324380234.pdfIn PDF document text
    • http://www.supair-lux.hu/ckfinder/userfiles/files/42882336381.pdfIn PDF document text
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/16132da991d323---72086404790.pdfIn PDF document text
    • http://www.39koratmachinery.com/file_upload/files/fudizuniposirepekawizaf.pdfIn PDF document text
    • http://vietsonplastic.com/uploads/userfiles/file/85582423253.pdfIn PDF document text
    • https://www.domosystem.gr/ckfinder/userfiles/files/magoruwikosuxevo.pdfIn PDF document text
    • https://portalbime.com/UploadedFiles/New/file/84151499520.pdfIn PDF document text
    • http://ttmm.co.jp/ckfinder/userfiles/files/sijuxega.pdfIn PDF document text
    • http://gekon.net/userfiles/file/digadadusegiwe.pdfIn PDF document text
    • http://naturalfurnish.com/userfiles/file/44947600141.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/t2rco6eg5ro4kps3qgd1n5cupg/waxemotaxativeko.pdfIn PDF document text
    • http://hospitalityroyal.com/upload_files/file/xudokovomov.pdfIn PDF document text
    • http://farmaciafici.com/userfiles/files/jekagewekofapamolosa.pdfIn PDF document text
    • http://tecsun-moscow.ru/docs/file/45124838970.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_off0000b010.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB010 15564 bytes
SHA-256: f6ede0fa4ab39f5ae8a69b84f261b7474ced6ad686e14e2acb63c332f87c69a1
font_01_sfnt_off0000d729.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD729 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ef40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF40 10700 bytes
SHA-256: b75d59947a2e6a0b082ce064a2944bb16dd0a26fac2626451392b022a3d5a294