Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8d021fb2c2b16b7…

MALICIOUS

PDF

89.2 KB Created: 2021-10-07 13:47:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 03c52d6d2a5fddaa0ae51458de848eed SHA-1: c2d875ff0f2cca338085fad1d474c12f8b41eb6f SHA-256: a8d021fb2c2b16b755f367d17e5255c33ea96fbb0c26ddbd6c9cebc59eeee0b8
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URLs, many of which are hosted on disposable domains and appear to be part of a link farm, suggesting a phishing or malware distribution campaign. The PDF structure and embedded URLs align with common techniques for luring users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9913

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://coretry.ru/uplcv?utm_term=psychodynamic+theory+of+dreaming PDF link annotation
    • https://maviet.vn/upload/files/pujewolelot.pdfIn PDF document text
    • http://canxetaianhduc.com/images/file/36882460977.pdfIn PDF document text
    • http://kimkhimientrung.com/uploads/image/files/93625827604.pdfIn PDF document text
    • http://anonelectronics.com/admin/fckeditor/editor/filemanager/connectors/php/upload_jpg/file/202109191253533089.pdfIn PDF document text
    • http://shepardinteriordesign.com/rw/upload/file/51211739880.pdfIn PDF document text
    • http://ttfi.org/app/webroot/userfiles/file/xizovigig.pdfIn PDF document text
    • http://degeninhotel.ru/admin/ckfinder/userfiles/files/limatarobemixu.pdfIn PDF document text
    • https://calienglish.com/ckfinder/images_store/files/90333163196.pdfIn PDF document text
    • http://clubselectionvoyages.net/images/file/45279368234.pdfIn PDF document text
    • http://el-system.jp/uploads/2012/files/gezefiwosavukogiwifikuf.pdfIn PDF document text
    • https://vadihosting.com/calisma2/files/uploads/busowulufejatukasutugode.pdfIn PDF document text
    • https://pointwebhost.com/calisma2/files/uploads/silidizupikawuzosutij.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/d47t2ehe5s3bso25mkcv85a6r3/duzexovepiwo.pdfIn PDF document text
    • https://aimtronu.org/userfiles/file/99200319314.pdfIn PDF document text
    • http://www.vandiestbrandstoffen.be/uploads/files/83515184323.pdfIn PDF document text
    • https://thebottombillion.org/business_school/uploads/file/lunoxigoxibeb.pdfIn PDF document text
    • http://digitalpolicycouncil.org/imagenes/file/duteramepalinifivejise.pdfIn PDF document text
    • http://zhengfutz.com/v15/Upload/file/2021941430511659.pdfIn PDF document text
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615226de27b8b---30711108390.pdfIn PDF document text
    • https://lifecareproduct.in/ckfinder/userfiles/files/82427410903.pdfIn PDF document text
    • http://jinruily.com/UploadFile/file/20210923042757416.pdfIn PDF document text
    • http://autolubitel-irk.ru/userfiles/file/55059930018.pdfIn PDF document text
    • https://www.sesc-am.com.br/Selecao/ckfinder/files/37183524331.pdfIn PDF document text
    • http://apvn.info/userfiles/file/56011375212.pdfIn PDF document text
    • http://autolavaggiocraparotta.it/userfiles/files/xogesoneminevaraxamoviwiv.pdfIn PDF document text
    • http://stilna-ya.com/_userfiles/file/kuxubupilizabevujeke.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_off0000f581.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF581 18736 bytes
SHA-256: b27ffc9f5c4d2f6fe48fcfb07a7b0b67a3ff2467a120fa026abc208faa87dad3
font_01_sfnt_off00012577.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12577 10992 bytes
SHA-256: 582bb7d357509c7f386776f0aa4b05f044d062ec2a4424ad8edd635966bfcc07
font_02_sfnt_off00013ea8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13EA8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1