Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4427fd043aac6d0…

MALICIOUS

PDF

87.1 KB Created: 2021-09-22 15:20:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 66302a0404f8a7f5b3e58cb8c0c667fe SHA-1: 7dabe27f188ed0911158b48cf48f905c9a10c170 SHA-256: c4427fd043aac6d0667f5e0d01c5c474c0e659f14459316ed4416a0d6f40b573
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to compromised WordPress sites and other domains, indicative of a link farm designed to redirect users to malicious content. Heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest this malicious intent. The ML classifier and ClamAV detection further confirm its malicious nature, likely serving as a lure for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 https://infrive.ru/uplcv?utm_term=oreo+tv+for+download PDF link annotation
    • http://fedime.org/imagenes/degavadubamaravenare.pdfIn PDF document text
    • http://bjjiffy.com/upload/32979809895.pdfIn PDF document text
    • http://flooroverstock.com/admin/userfiles/file/fizot.pdfIn PDF document text
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161427501e24f3---davegajekef.pdfIn PDF document text
    • http://ordinate-ltd.com/file_media/file_image/file/gefokabezu.pdfIn PDF document text
    • https://grupo-kayros.com/userfiles/file/wekifoxozanesujipakizan.pdfIn PDF document text
    • http://geojeoceanhotel.com/userfiles/file/20210905031542.pdfIn PDF document text
    • http://zrdb-drogbud.pl/Upload/file/25464970879.pdfIn PDF document text
    • https://palezieux.com/ckfinder/userfiles/files/92513736935.pdfIn PDF document text
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/2e1d08530de64b00064b592bf117f9dc/2002606171.pdfIn PDF document text
    • https://snowcat.pl/admin/ckfinder/userfiles/files/39787280616.pdfIn PDF document text
    • https://karlschool.org/uploads/files/202109031237415441.pdfIn PDF document text
    • https://cathita.vn/upload/files/xixerudo.pdfIn PDF document text
    • https://budapestpainter.hu/ckfinder/userfiles/files/11541833091.pdfIn PDF document text
    • http://uralcomservis.ru/crn_fls/crn_files/5200949580.pdfIn PDF document text
    • http://m-camper.ru/ckfinder/userfiles/files/11763920389.pdfIn PDF document text
    • https://fancybox.pamlskovnik.cz/ckfinder/userfiles/files/79790977358.pdfIn PDF document text
    • https://lederstuhlshop.de/ckfinder/userfiles/files/45752462759.pdfIn PDF document text
    • http://ozdesignhouse.com/app/webroot/uploads/files/jozaremavokosexivunil.pdfIn PDF document text
    • http://sjzhtchem.com/upload/files/45785516244.pdfIn PDF document text
    • http://leylasuren.com/images/userfiles/imagefile/toronoren.pdfIn PDF document text
    • https://growlocals.com/wp-content/plugins/super-forms/uploads/php/files/dee2d23c6efb603c71b42c9d5ccfe4aa/74560420051.pdfIn PDF document text
    • http://dragonspond.com/uploads/files/guvatekowidisabup.pdfIn PDF document text
    • http://easytravel63.ru/ckfinder/userfiles/files/zixupimugemewa.pdfIn PDF document text
    • http://www.taxivanclass.com/uploads/ckfinder/files/ganiditomolebixoso.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_off0000e7c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7C3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ffda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFDA 10264 bytes
SHA-256: f543125780a4e10abfdcd97d91828ec679158044199837002cd0f19a030ca4d5
font_02_sfnt_off00011722.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11722 21568 bytes
SHA-256: e6f934cbf9291c8ccd02ddc07e585285fc6da08662ae173eaa4bb507541dc7ca