Malicious PDF — malware analysis report

Static analysis result for SHA-256 ad31da5e8a6fbc9c…

MALICIOUS

PDF

93.8 KB Created: 2021-07-29 20:49:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 721208442db95d804eb64affe9888da7 SHA-1: dd4878e27a067cd5975e9935e8d4e3eb72c381ed SHA-256: ad31da5e8a6fbc9c35abb8611e9b37544bbcdfc7c241be948cdb9c5684de58b8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link farm with numerous URLs, several of which point to compromised CMS upload storage, indicating a phishing or malicious redirection attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to lure users to malicious sites or download further malware. No scripts were extracted, and the document body was unreadable binary data.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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://irrisyst.eu/files/file/77828154543.pdf In PDF document text
    • http://cafesezony.ru/fck_editor_files/files/58814120371.pdfIn PDF document text
    • http://kiavysocina.cz/UserFiles/File/3225130787.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/1hm3u7pbd4traiekkdccuv77er/95189309731.pdfIn PDF document text
    • http://yngc.ru/admin/ckfinder/userfiles/files/10151983559.pdfIn PDF document text
    • https://dondepodemosir.com/userfiles/file/17380446282.pdfIn PDF document text
    • http://sosnovgeo.ru/userfiles/file/ruguzubaxur.pdfIn PDF document text
    • http://www.veronicaneal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/1607af56e78552---vijizuf.pdfIn PDF document text
    • http://fitviewer.biz/files/file/85410539574.pdfIn PDF document text
    • http://altiro.nl/home/tjerk/file/didagojigan.pdfIn PDF document text
    • https://tort-art.ru/userfiles/file/tasuxokupemamojuxunutoso.pdfIn PDF document text
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/5tbmuepu9rk1u09oj5jmgmeal3/93193811754.pdfIn PDF document text
    • http://strandedtattoo.net/file/60241925585.pdfIn PDF document text
    • https://carrieres-pierre.com/userfiles/file/97510475662.pdfIn PDF document text
    • https://isosklo.cz/uploads/foriwavanasuwadikati.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/itranrk4vppv4jun0151nhlko7/mezot.pdfIn PDF document text
    • https://dewalt-naradi.cz/media/upload/editor/file/guromagofoposalepukesim.pdfIn PDF document text
    • https://hopefor.today/wp-content/plugins/super-forms/uploads/php/files/e021e0a3bedc2a5390c1ad7d0f6e20e7/xudizijaxuzijit.pdfIn PDF document text
    • http://atlantichomeportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c04c10d2a5b---jarubapefizonu.pdfIn PDF document text
    • http://koszyczarek.pl/userfiles/file/gabuzu.pdfIn PDF document text
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160ff75ff03eb4---79022300560.pdfIn PDF document text
    • http://www.dramayaramendes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607e669636b1d---womuxarelinoru.pdfIn PDF document text
    • http://biurod9.pl/public/userfiles/file/55419192785.pdfIn PDF document text
    • http://vhs1962.com/clients/b/b9/b967f936f519796c2a696a6ed1da67f9/File/pugogot.pdfIn PDF document text
    • https://www.clubmanizales.com.co/wp-content/plugins/formcraft/file-upload/server/content/files/160cd6a69883b0---51111281791.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=html+to+pdf+with+phantomjsPDF 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_off00010951.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10951 17672 bytes
SHA-256: 510f810c680feafe645f3ff4cbe3b82e254c98fd80d83331fff82074e2d62701
font_01_sfnt_off0001372d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1372D 10736 bytes
SHA-256: 5233a7cb0e38b5ed2b9d6a6d549b8c98fc0d07b90c4697a11dc445d007158cad
font_02_sfnt_off00014f9c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14F9C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1