Malicious PDF — malware analysis report

Static analysis result for SHA-256 28d8c70c97fc538f…

MALICIOUS

PDF

81.8 KB Created: 2021-09-07 02:00:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: af95ff58d42e104b01ab1a7bb62fb5f4 SHA-1: 5754c2ee35ad7e499c240e101ecf61d3449dd430 SHA-256: 28d8c70c97fc538f3751dc4a62450ed1900ac1e680e91aa3d1b19bb8226662e4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress upload sites and other disposable hosting domains. These links are designed to appear as search results or file downloads, likely to facilitate phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://pistant.ru/uplcv?utm_term=honeywell+top+fill+warm+mist+humidifier+manual PDF link annotation
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bda8e50a747---5096458880.pdfIn PDF document text
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1608ec5372eac3---sebazazanuvedezomol.pdfIn PDF document text
    • https://www.dishdivvy.com/wp-content/plugins/super-forms/uploads/php/files/55b71cef10aa750efb5e0e7d99a40f98/79211483640.pdfIn PDF document text
    • https://jv-cms.crazy-jessie.nl/uploads/files/19996270136.pdfIn PDF document text
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160c53ce65d0fb---medodesutuwu.pdfIn PDF document text
    • http://imapbook.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/64085273343.pdfIn PDF document text
    • http://sochi-riba.ru/ckfinder/userfiles/files/terikomeremenubuluxog.pdfIn PDF document text
    • http://www.johnknox.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160837a837d346---mibiwura.pdfIn PDF document text
    • https://drsaman.com/files/taruzirufaf.pdfIn PDF document text
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/160c4cd711a5d3168c15423bfe7718f7/42001218576.pdfIn PDF document text
    • http://aucoindeshalles.fr/menu/file/sogisomipub.pdfIn PDF document text
    • https://scavilecis.it/userfiles/file/93523067459.pdfIn PDF document text
    • http://acpiindia.com/userfiles/file/27582915052.pdfIn PDF document text
    • http://shengnabei.com/uploadfile/file///2021080811151938.pdfIn PDF document text
    • https://terravistahometeam.com/wp-content/plugins/super-forms/uploads/php/files/ee1b8ceb347c6fdf556679b6d535bec2/28098000315.pdfIn PDF document text
    • https://luxurytravel-show.com/wp-content/plugins/super-forms/uploads/php/files/00dd46ba43b29559bcf59bbcb25d64a8/gapomoj.pdfIn PDF document text
    • http://shreejians.com/userfiles/file/51401209760.pdfIn PDF document text
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160959cec15c13---sumorujom.pdfIn PDF document text
    • http://foto-video.ch/userfiles/files/tivejenesu.pdfIn PDF document text
    • http://dietetyka-24.pl/images/files/delafidulabuwux.pdfIn PDF document text
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/afcm0bgrn2stuupcne0d0ul5b6/poxifojonadifexutudadu.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a843eb18442---badowewuzopekasigot.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_off0000d88a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD88A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f09c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF09C 17900 bytes
SHA-256: 292baf25f6af494aac86758d40db921917334bec990b90f36e91fb436a8e4f5f
font_02_sfnt_off00011f88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F88 11056 bytes
SHA-256: dfa7d039d9b70f5c685af4248c2bc17c1f06d938a3a43c21cc487cbd727ba97f