Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8cbf0f2d177bf2d…

MALICIOUS

PDF

77.3 KB Created: 2021-09-01 09:19:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: be8d36aa29132fc728e27dcf873a6f18 SHA-1: cc3e136cbc89cc05cb9e3b57fced3d0c089657d3 SHA-256: c8cbf0f2d177bf2dc293e3df9de2885cf50d4e4eb97a976d8fea0c145258a6cf
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and contains embedded JavaScript. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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://www.stemcellhairclinic.com/files/files/25213778012.pdf In PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c8fdcb73e55---56700863036.pdfIn PDF document text
    • http://divapharma.com/uploaded/file/18865404751.pdfIn PDF document text
    • https://www.plsok.com/wp-content/plugins/super-forms/uploads/php/files/cfd5a1e36870bc27136bb2203e01f136/didedoburev.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/e930b7a325a4567d33fcaa4d0530e7a5/pisowezizu.pdfIn PDF document text
    • http://cochemical.com/upload/files/67285013497.pdfIn PDF document text
    • https://engineeredrepinc.com/wp-content/plugins/super-forms/uploads/php/files/4b594e9748c355d0d47150c71ca6c7d5/bewebiboniro.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609b65aac23d5---busamunekiwan.pdfIn PDF document text
    • http://arserwood.com/js/fckeditor/editor/filemanager/connectors/php/connector.php/upfiles/file/210504050546047116s4gb8j.pdfIn PDF document text
    • http://cathugo.de/res/wysiwyg/file/2586836432.pdfIn PDF document text
    • http://clear-es.net/yamituki-n/uploads/files/54127756527.pdfIn PDF document text
    • http://okna-stv.ru/userfiles/files/66722924541.pdfIn PDF document text
    • https://assignmentmart.com/ckfinder/userfiles/files/61367713339.pdfIn PDF document text
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c24ecaeb92---65753853423.pdfIn PDF document text
    • http://www.mtpartnersfl.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfd2bc9c6c7---33459768773.pdfIn PDF document text
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/0a5aed4abde2b1891841f2b5196e4cd6/20227595806.pdfIn PDF document text
    • http://flemingfamilies.org/clients/8/8a/8af36a28baf44bfc7b8a7004fb4eaede/File/golabujavonomasobi.pdfIn PDF document text
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/161013499252f6---bofizene.pdfIn PDF document text
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4cc22cf98f---kemuninud.pdfIn PDF document text
    • https://nhachoxebus.com/upload/fck/file/63164005563.pdfIn PDF document text
    • https://groupunsur1.com/contents//files/50401427840.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=critical+care+guidelines+2019+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_off0000cb80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB80 11268 bytes
SHA-256: eaad36891aefd81c65472ea54e919f976233a443c12e2427300f662120028c98
font_01_sfnt_off0000e5f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5F8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fe0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE0A 16096 bytes
SHA-256: 1bff63a86b7d77e98f15e0a3060b025eadd5208996d110cb94fd54f5e5fb43a6