Malicious PDF — malware analysis report

Static analysis result for SHA-256 611e8d4603511b7d…

MALICIOUS

PDF

87.5 KB Created: 2021-08-14 20:37:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: b5632fb6cb937105a628a604334e546d SHA-1: aac8ec1285feb5c2b1afbfb4495010b5c1dffce3 SHA-256: 611e8d4603511b7d7f8458383e4ef6c269926051185c875814fc4122e90d55f3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains numerous links to external websites, many hosted on compromised WordPress sites, suggesting a link farm or phishing lure. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a pattern of using disposable hosting for these links, further supporting a malicious intent to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://nomylo.ru/uplcv?utm_term=watch+faces+for+apple+watch+6 PDF link annotation
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/6juns68vtbk5psk02l60bveecd/tiwimedibupokonazu.pdfIn PDF document text
    • http://starlightcelebre.org/clients/4/43/43e9139217482d7666ce300faf566241/File/75038552336.pdfIn PDF document text
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/160f5fbfdef808---58851965791.pdfIn PDF document text
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1609f061de230c---mubikitadove.pdfIn PDF document text
    • http://www.dr.schure.net/ckfinder/userfiles/files/zezexizagujonanapizas.pdfIn PDF document text
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/0622f3563284736cbe91ab1fabb5708c/vumudi.pdfIn PDF document text
    • http://www.moteco.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16090e5b7a4c29---45031659389.pdfIn PDF document text
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/160edfe15e0610---kuwosomufiwaxugovatanegig.pdfIn PDF document text
    • https://kueapem.com/contents//files/16354296221.pdfIn PDF document text
    • https://www.eecpowerindia.com/codelibrary/ckeditor/ckfinder/userfiles/files/junewotajiru.pdfIn PDF document text
    • http://alexsrmenchion.com/clients/b/bf/bf5401b25fe3457642f5a6f1150d5537/File/76161538574.pdfIn PDF document text
    • http://www.caslyn.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160e0356e0c260---dowotivepib.pdfIn PDF document text
    • https://marbellamohali.com/wp-content/plugins/super-forms/uploads/php/files/ebe9a294a0aa5b7d5477993e1419b8cf/weginufojaf.pdfIn PDF document text
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fcb7b82f317---878267310.pdfIn PDF document text
    • http://neodev.space/wp-content/plugins/formcraft/file-upload/server/content/files/160b4095bb1217---7739758672.pdfIn PDF document text
    • http://www.mywil.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1609757a0bf38b---vagiwabepodojalozupine.pdfIn PDF document text
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/16096bbbc22953---76091959564.pdfIn PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/ejbkk4vcnegnmm4j9gnaijmeoo/60548861350.pdfIn PDF document text
    • https://wemservice.com/ckfinder/userfiles/files/givalavovuneburozaxevex.pdfIn PDF document text
    • https://pacie.vn/web/uploads/files/20150634657.pdfIn PDF document text
    • https://pensiuneavalentina.ro/app/webroot/file/86051297090.pdfIn PDF document text
    • http://oreade-breche.fr/userfiles/file/33191211143.pdfIn PDF document text
    • https://vestol.bg/files/file/60536113269.pdfIn PDF document text
    • https://myparrotfood.com/user_files/files/zufigidalufiruvalusibu.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_off0000f17a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF17A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010991.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10991 10628 bytes
SHA-256: 272e0ebd7b8cdc0973f17bd8b692cbab6d7a86247b03539cd78a9ce82c371c63
font_02_sfnt_off00012230.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12230 17936 bytes
SHA-256: e5489c8cb3627018cc21a323f2d2991e85053eded011141eea5d183aa3205a27