Malicious PDF — malware analysis report

Static analysis result for SHA-256 05a3f560d960a7d7…

MALICIOUS

PDF

91.9 KB Created: 2021-07-31 11:09:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: f30cfed3c8d700993b1f552a4d3dbb21 SHA-1: 45d3f99294c00e591293f369abead278214fb928 SHA-256: 05a3f560d960a7d7858d827343712c2c170617b16e2349424cda4d6691cdca8e
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a link farm with numerous URLs pointing to compromised WordPress sites, suggesting an attempt to redirect users to potentially malicious content or for SEO manipulation. The ML classifier strongly flagged this PDF as malicious. No scripts were extracted, and the document body was unreadable binary data, limiting further analysis of specific user lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

Heuristics 5

  • 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 http://kuhomania.ru/ckfinder/userfiles/files/56348487941.pdf In PDF document text
    • https://ercrs.org/wp-content/plugins/super-forms/uploads/php/files/32squsiu7erda42jd57qbhhom4/rowukiwe.pdfIn PDF document text
    • https://sellos-mecanicos.com/wp-content/plugins/super-forms/uploads/php/files/cea6d038e65ffad32c21b03b12487a26/nopiruwufokomibotu.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/160949d137697a---zuzaxam.pdfIn PDF document text
    • https://www.certificagreen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9b1681c37b---35553219034.pdfIn PDF document text
    • https://etre-cheval.fr/Applications/MAMP/htdocs/etre%20cheval/news_pix/file/wejube.pdfIn PDF document text
    • http://mognational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d2b6ab7c96---jofokagadam.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b891c451920---50246198195.pdfIn PDF document text
    • http://easternsheep.by/app/upload/file/nodezadarupusudiluxizu.pdfIn PDF document text
    • https://regenerativetherapyforpain.com/wp-content/plugins/super-forms/uploads/php/files/526b12ca612296e6ee34d4c1d7d0a802/61223326756.pdfIn PDF document text
    • https://neavocats.com/wp-content/plugins/super-forms/uploads/php/files/78e89af48d776e8bbe4dff933db0ed03/1173421280.pdfIn PDF document text
    • https://sitebyside.ru/wp-content/plugins/super-forms/uploads/php/files/73d5076b9c0a76413301933476c8c73c/josiwixipogumoxusigox.pdfIn PDF document text
    • http://thallo-food.hu/uploads/ckfinder/userfiles/files/43675273443.pdfIn PDF document text
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4c49376cba---baxebizukewuloxi.pdfIn PDF document text
    • http://szkolaprywatnaleszno.pl/userfiles/file/43167955558.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ffd07ae30d6---25791345020.pdfIn PDF document text
    • http://www.hollyskauaicondo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d3271a821cc---xigofikufexupijuzobileru.pdfIn PDF document text
    • http://bellsazshihtzu.com/clients/878694/File/14653773154.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16072bba123f5a---rozawoxunisasaribilu.pdfIn PDF document text
    • http://www.nowsingapore.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/16089b146b84f3---19109904947.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160949021d757b---38237798304.pdfIn PDF document text
    • http://anhuishangbiao.com/upload_fck/file/2021-5-25/20210525174810459230.pdfIn PDF document text
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160e01d471a51d---dowetisokiwi.pdfIn PDF document text
    • https://gradeagroup.com/wp-content/plugins/super-forms/uploads/php/files/v11b8j3r0k6d1ql0dr7serjnt0/fijoguniguxujabivirodudam.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=uma+jornada+atrav%C3%A9s+do+tempo+livro+pdfPDF 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_off0000fade.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFADE 20488 bytes
SHA-256: 165e44247016a6fe9eab3fe7a2c98b9eada59df17be65cf6808c36a595f2128f
font_01_sfnt_off00012cac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12CAC 11016 bytes
SHA-256: 1ad7150793657d781636ce79e79bc1ffc64e71bd85a8e82b14f1904a76774ee3
font_02_sfnt_off000145f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x145F0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1