Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7e83e4b79a0e244…

MALICIOUS

PDF

85.5 KB Created: 2021-09-22 20:08:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 3f96533e9d1cdfbbd44fc148404bddde SHA-1: 7462aa7c8951ebe3fbeefb2fce63fb249d76d43d SHA-256: a7e83e4b79a0e2440b6f4e1d745c2807d5129c93f0088af096fc4e41f697e2ee
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, supporting the conclusion that it is used for malicious redirection or to host further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 6

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://polimak.pl/userfiles/file/27601627824.pdf In PDF document text
    • https://acethamessecurity.co.uk/wp-content/plugins/super-forms/uploads/php/files/ddc41bca7e7de1ee2b51fff5d15812a2/4475729501.pdfIn PDF document text
    • https://www.retake.dk/ckfinder/userfiles/files/88210176443.pdfIn PDF document text
    • https://asaptransfers.co.uk/wp-content/plugins/super-forms/uploads/php/files/4ebc7b2f182e0a35d84106f11fc7aa35/retutiduroxobolife.pdfIn PDF document text
    • http://laconchigliacasevacanze.it/userfiles/files/fabel.pdfIn PDF document text
    • http://romovi.net/sgi_userfiles/userfiles/files/97541792237.pdfIn PDF document text
    • http://leylasuren.com/images/userfiles/imagefile/4462791458.pdfIn PDF document text
    • http://hatowo.com/app/webroot/uploads/files/64649441007.pdfIn PDF document text
    • http://fosterfreezesantarosa.com/uploads/files/88142898170.pdfIn PDF document text
    • http://www.thegrcinstitute.org/app/webroot/js/ckfinder/userfiles/files/84828361406.pdfIn PDF document text
    • https://orig-shop-gsm.ro/ckfinder/userfiles/files/zalawo.pdfIn PDF document text
    • https://malimbe.africa/wp-content/plugins/super-forms/uploads/php/files/3dd00a23ec3d6cd166fc717d0e9a1085/zajisivum.pdfIn PDF document text
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/bc6d1c9b47e454ce230ae27e11e9dcdb/novisaj.pdfIn PDF document text
    • https://jv-cms.crazy-jessie.nl/uploads/files/23612187241.pdfIn PDF document text
    • http://ingore.cn/upload/files/45198045038.pdfIn PDF document text
    • http://www.megasaludips.com/wp-content/plugins/formcraft/file-upload/server/content/files/161421646d053a---pizeduwategusogokuwul.pdfIn PDF document text
    • http://hortherbpublisher.com/files/upfiles/file/fanobel.pdfIn PDF document text
    • http://guojingmall.com/userfiles/file///17502603458.pdfIn PDF document text
    • http://fatamorgana.fr/uploads/assets/file/verepexujazedixan.pdfIn PDF document text
    • http://jtravel.clickis.kr/FileData/ckfinder/files/20210915_1C640014A9938A72.pdfIn PDF document text
    • https://0955205219.jwa.tw/userfiles/files/jedatepapitiwajiripa.pdfIn PDF document text
    • http://wedding-ideas.ru/ckfinder/userfiles/files/ribipojibe.pdfIn PDF document text
    • https://gea99.com/ckfinder/userfiles/files/bekixogigo.pdfIn PDF document text
    • https://taybaite.com/userfiles/file/10117917392.pdfIn PDF document text
    • https://konteshamamotu.com/userfiles/file/mejanaxiguxepop.pdfIn PDF document text
    • http://eskuvotoszkanaban.hu/editor_up/lupajomonazejibumapisido.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=how+to+transfer+sms+messages+from+one+android+phone+to+anotherPDF 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_off0000e57d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE57D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fd8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD8F 17992 bytes
SHA-256: e0fe045e03ec7e4d39a1466fd7fce55134afaed1225ab55ac428daeeecdc2d4b
font_02_sfnt_off00012c42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C42 10976 bytes
SHA-256: 293c424a47de4312bed48b72636d7b5ee99643fd8fdb8e92ae2d0772fa18e166