Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca41a8a64c4f94d0…

MALICIOUS

PDF

98.4 KB Created: 2021-09-18 13:15:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: f962def6313058e63c16319be85d8771 SHA-1: 1e6dddd645ed65b447bb23b6b7dd17e4b1014f98 SHA-256: ca41a8a64c4f94d0040a62b0e668a662f38d2a7339e5618d50eccef17b1c08e8
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by multiple heuristics, including a high ML score and ClamAV detection as a phishing trojan. It contains numerous embedded URLs, many of which point to disposable hosting, suggesting a link farm or phishing lure. The document body is heavily obfuscated and unreadable, but the presence of external URIs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic strongly indicate a malicious intent to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://synerhu.ru/uplcv?utm_term=change+carrier+name+android+without+root PDF link annotation
    • https://hatinhjobs.com/upload/files/doferulosipefaviw.pdfIn PDF document text
    • https://cristiandellavedova.com/wp-content/plugins/super-forms/uploads/php/files/d74c6d5bb2c8fcc0a154c57baa52c4e2/lazegudure.pdfIn PDF document text
    • http://smenergy.kr/uploaded/file/7970089256142bbc1f0d6e.pdfIn PDF document text
    • http://sinoscaform.com/upload/ckimg/files/202109120703083706.pdfIn PDF document text
    • http://circolonauticofavignana.it/userfiles/files/73731026942.pdfIn PDF document text
    • http://nincity.de/inline/file/wipak.pdfIn PDF document text
    • http://cimkezes.hu/uploads/ckfinder/userfiles/files/posufuvuxafukiz.pdfIn PDF document text
    • http://chayka-svg.ru/files/44184390425.pdfIn PDF document text
    • https://eetravel.net/file/buriwuk.pdfIn PDF document text
    • http://www.alliance-bio.com/user_data/editor/ckfinder/core/connector/php/upload/files/gowurajedovuwukajepidaw.pdfIn PDF document text
    • https://tepatsasaran.com/contents/files/49300315835.pdfIn PDF document text
    • http://derp74.fooden.com/UserFiles/files/93321722218.pdfIn PDF document text
    • http://stopguepes72.fr/userfiles/file/35273296811.pdfIn PDF document text
    • http://fioredda.com/userfiles/files/fozefakupolatixag.pdfIn PDF document text
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161402b26f2fea---bizukevumadutemaniluvi.pdfIn PDF document text
    • https://acp-luxusingatlanok.hu/ckfinder/userfiles/files/26222652190.pdfIn PDF document text
    • http://vizugy.hu/uploads/files/simogas.pdfIn PDF document text
    • https://jdsliquorlocker.com/nbloom/fckuploads/file/25627954417.pdfIn PDF document text
    • http://ambvetsanprospero.eu/userfiles/files/61073981001.pdfIn PDF document text
    • http://27derajat.com/assets/ckfinder/core/connector/php/uploads/files/17502941107.pdfIn PDF document text
    • https://asmitahrgroup.com/ckfinder/userfiles/files/folovuwoze.pdfIn PDF document text
    • http://npxbyy.com/wang3_3_10_27/Upload/Upload/file/202194949556547.pdfIn PDF document text
    • http://hyunsin.net/userfiles/file/41284472012.pdfIn PDF document text
    • http://lex.tj/img/file/kopegabixope.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_off00011926.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11926 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001313d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1313D 10820 bytes
SHA-256: 3ee2e32c13d6eb2f18f709a292e4995411491b7249c0d7f156c8b78b19138b47
font_02_sfnt_off000149db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x149DB 18916 bytes
SHA-256: f99844b2e7f6f361fd05bd30b5c9737f93e58e59fed43cc6c12e625bdfbc9d87