Malicious PDF — malware analysis report

Static analysis result for SHA-256 a05c23e8217f1cf9…

MALICIOUS

PDF

93.5 KB Created: 2021-07-20 19:55:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 5d7f887ef964bec143693a8581550cb3 SHA-1: d1b927fb36c6653301db4f5435f0f51a2a8e5850 SHA-256: a05c23e8217f1cf95a4a37e8fc2dbfb75f4579e59ea647f665bfc94e29acd86c
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to distribute further malicious content or phish users. The document body was unreadable, but the presence of numerous external links and the overall detection profile strongly indicate a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9820

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/pjf0ksqgr67d6ss9edos5b5tqe/57741483861.pdf In PDF document text
    • https://lemanssrl.it/file/savowarugavo.pdfIn PDF document text
    • http://comlark.ru/userfiles/files/66535182118.pdfIn PDF document text
    • https://hartwellcook.com/wp-content/plugins/super-forms/uploads/php/files/0100595ca8a09851ad6a97c54ebe63c2/rafez.pdfIn PDF document text
    • https://www.phoenixdentalacademy.co.uk/wp-content/plugins/super-forms/uploads/php/files/b203801a762a72b0b7b39de7d738e3e5/39094906527.pdfIn PDF document text
    • http://burattinojatek.hu/userfiles/file/manolesizulave.pdfIn PDF document text
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a445026a0c4---vufadifinidulupazerojize.pdfIn PDF document text
    • https://coffeetuanvang.com/Images_upload/files/nobeg.pdfIn PDF document text
    • http://hilimall.ae/uploads/files/95719219514.pdfIn PDF document text
    • http://vipavtoufa.ru/wp-content/plugins/super-forms/uploads/php/files/7f46e4df2b42641749ff3be7202ab31e/59317632968.pdfIn PDF document text
    • http://xn--80akazwaeiw.xn--p1ai/editorfiles/file/mujolonigobewilerepu.pdfIn PDF document text
    • https://cqc-material.com/app/webroot/userfiles/files/forukigosumujemogokuwibo.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160da9c3c299ea---ruxikapu.pdfIn PDF document text
    • https://veritiesinstitute.com/wp-content/plugins/super-forms/uploads/php/files/56f3cac26413c2ab953a4bb0a20174e4/gidanatugupuz.pdfIn PDF document text
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/efa2231603e00b423126ee6047baae85/20941095311.pdfIn PDF document text
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b3722044046---15240797095.pdfIn PDF document text
    • http://delve-cr.com/uploads/nagojewesusirimesavik.pdfIn PDF document text
    • https://engravestone.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e6699659c01---vanopidazek.pdfIn PDF document text
    • https://marigabung.com/contents//files/58435107812.pdfIn PDF document text
    • https://www.cukoyem.com.tr/wp-content/plugins/super-forms/uploads/php/files/e73d5a32krt6vqshnkp30u3o30/xujapubapamef.pdfIn PDF document text
    • https://www.yoursurveysurveyors.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160f1eb8a5c1b9---vetiva.pdfIn PDF document text
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/9b66a88c9447b4572c7da9c0f1210a0f/10099750432.pdfIn PDF document text
    • http://sxhk365.com/uploads/file///duwenezuj.pdfIn PDF document text
    • http://mini-garden.ru/userfiles/file/41423449609.pdfIn PDF document text
    • https://stpetejazz.com/wp-content/plugins/super-forms/uploads/php/files/uh7unr6q8p8n099qb4rfsfgdnc/67407594750.pdfIn PDF document text
    • http://moscowfashion.net/content/xuploadimages/file/sopego.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=this+is+called+true+lovePDF 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_off00010b0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B0D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012324.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12324 10492 bytes
SHA-256: eff7176c88c01feaa15057c7f72fc326ad839c18ca0a52a4e8a985803c5e7c53
font_02_sfnt_off00013b2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B2B 17344 bytes
SHA-256: c5f0b95fe6142b6e1c55cddcdf46e9ec7610fc46d8b2e4bc54eb83c4548e0952