Malicious PDF — malware analysis report

Static analysis result for SHA-256 436ba899ec1060b4…

MALICIOUS

PDF

74.7 KB Created: 2021-07-19 07:54:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: b4946782a19dacd21381af478b94c203 SHA-1: 57d1ea3321206e228aa3851ee9857c9156a9b842 SHA-256: 436ba899ec1060b4f413b433e2f1bfd457826553dc73245c8a9a6eb567ab95c9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link farm directing to multiple compromised WordPress upload directories, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content but containing embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://www.bramfordgc.co.uk/ckfinder/userfiles/files/wujejujenimategurowijasin.pdf In PDF document text
    • https://www.lightingsolutionsal.com/wp-content/plugins/super-forms/uploads/php/files/50554706d474b531dcece5555c7593a4/73584209197.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160b8b73f2f593---galumazojomemaziwumoragiz.pdfIn PDF document text
    • https://ontime-taxi.kg/wp-content/plugins/super-forms/uploads/php/files/71489facf40ebef4286a7d6b6f2d5ed8/41976513705.pdfIn PDF document text
    • https://relleno-acidohialuronico.com/wp-content/plugins/super-forms/uploads/php/files/0895985e8b5aa0cd2359511dc4ec587e/kefolafufojotugezixotije.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607302d940a26---liwafatem.pdfIn PDF document text
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606cdc963c899---lupizixiwejoliledipi.pdfIn PDF document text
    • https://www.emmabowman.com/wp-content/plugins/super-forms/uploads/php/files/db52216c0ae15d43c24355a1fedc745b/wipajotat.pdfIn PDF document text
    • http://bahtiyardishekimi.com/fckfiles/file/56496116948.pdfIn PDF document text
    • http://szyldkj.com/luodan/images/userfiles/file/1072009747.pdfIn PDF document text
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16082811ac9036---49130056469.pdfIn PDF document text
    • http://veiligheidssloten.nl/ckfinder/userfiles/files/51484094731.pdfIn PDF document text
    • http://alliance-ic.ru/uploads/file/pajitabetirateverotomugam.pdfIn PDF document text
    • http://rsst77.ru/upload/files/seziraxidisonuguk.pdfIn PDF document text
    • http://hersheyhigh1981.com/clients/37302/File/70341634716.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607576baf2eb1---27375314576.pdfIn PDF document text
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f3d35c48dcb---jalewobijipuwubi.pdfIn PDF document text
    • https://soechi.com/userfiles/file/8775881549.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/6a354cc2gtqp8njhehpkaitdnq/74165668988.pdfIn PDF document text
    • http://www.teeintact.com/admin/fckeditor/editor/filemanager/connectors/php/img/file/bixebawogoromixigupesi.pdfIn PDF document text
    • http://alexanderkanevskyartistbiography.com/clientMedia/file/nepatipobegemerixe.pdfIn PDF document text
    • http://andreevmag.com/wp-content/plugins/super-forms/uploads/php/files/b924dcc6f6648ed6868ed5bebf7f76e9/41064811301.pdfIn PDF document text
    • https://hacunamatata.ru/wp-content/plugins/super-forms/uploads/php/files/841916c61acbba21994b80fb4e5e6694/pexarijuvifapewaz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=i+wanna+be+loved+by+you+just+youPDF 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_off0000c111.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC111 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d923.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD923 16668 bytes
SHA-256: 191326bff8355aea540f3823067ebc4e138a558b4f036b8f4e6c4d8a400c9bfc
font_02_sfnt_off000104ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104CE 10636 bytes
SHA-256: 8659670fef9a620b791cdcb109a31c3296cd484a854a46b6dc11c0514c89228c