Malicious PDF — malware analysis report

Static analysis result for SHA-256 9210b9cad5f79c31…

MALICIOUS

PDF

93.6 KB Created: 2021-09-03 20:17:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: bf24e40036f6c0e9a31aa55f76ca4490 SHA-1: 535f5c9a43bf141c0c10eea07e438e2eec90a446 SHA-256: 9210b9cad5f79c3194327ab6c527c5b536b9f105365e480a1ad18b62066a25d5
236 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File T1059.001 PowerShell

This PDF file was flagged by ClamAV as a phishing trojan. Heuristics indicate it uses social engineering lures, instructing the user to copy/paste commands into a shell or install a fake browser extension. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, but the presence of multiple links to compromised CMS upload storage and disposable hosting suggests a link farm used for distributing malicious payloads. The primary attack pattern involves tricking the user into executing malicious code.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9897

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Clipboard command execution lure high SE_CLIPBOARD_COMMAND_LURE
    Document tells the user to copy or paste clipboard content into Run, PowerShell, cmd, or another shell-like execution context
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160becc0ee8ede---12212294214.pdf In PDF document text
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b25d06c0a40---34009792996.pdfIn PDF document text
    • http://sparan-art.ru/ckfinder/userfiles/files/tudasutixoxusirikemirusu.pdfIn PDF document text
    • http://rockhousemethod.com/ckfinder/userfiles/files/sovujutofosimivaxeti.pdfIn PDF document text
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c8cb1d5015---zulomerexumi.pdfIn PDF document text
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afa5463865a---pivexemajem.pdfIn PDF document text
    • https://jmtours.co/aym_image/files/45932283180.pdfIn PDF document text
    • https://basalyemek.com/ckfinder/userfiles/files/jufovepofagivoxolix.pdfIn PDF document text
    • https://travelinnsuites.com/nbloom/fckuploads/file/56594788909.pdfIn PDF document text
    • http://ylphs.com/ckfinder/userfiles/files/5938717166.pdfIn PDF document text
    • https://leunamgroup.com/wp-content/plugins/super-forms/uploads/php/files/ab0914dada862acb9215a130b99a3fe8/55615300660.pdfIn PDF document text
    • http://cioccolatogallucci.it/userfiles/file/voradaxasilipelur.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/1609face9a5932---97679390270.pdfIn PDF document text
    • http://jnnycc.org/userfiles/file/zimul.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607df70c7872e---55636105007.pdfIn PDF document text
    • http://lso-msm.fr/userfiles/file/fevejilukinitevevowekor.pdfIn PDF document text
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093b64164633---tewigoxabejuzix.pdfIn PDF document text
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160dde65947d63---29044780292.pdfIn PDF document text
    • http://burrburroughsfamily.com/clients/55468/File/patumavilukemutidat.pdfIn PDF document text
    • https://indirimlipin.com/calisma2/files/uploads/vawudamuvuzevake.pdfIn PDF document text
    • http://someteme.com/archivos/_20210702031629.pdfIn PDF document text
    • http://zulaikhatextile.com/userfiles/files/sarudawiduforinanaxa.pdfIn PDF document text
    • http://raduzhniy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd33ccd2584---nuvidimujetakamelem.pdfIn PDF document text
    • http://auto-spec.ca/fck/file/sakegedivumujuzejulewe.pdfIn PDF document text
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a80ec7c144e---33043176514.pdfIn PDF document text
    • https://independentmusicleague.com/wp-content/plugins/super-forms/uploads/php/files/733acd79a8c557bf8c099e615b636829/sewejavidarug.pdfIn PDF document text
    • http://nuyewpilot.academy/wp-content/plugins/super-forms/uploads/php/files/1cffdbcf7a12190d6193519ad20b37cd/80281335692.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=axure+rp+8+tutorial+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_off00010add.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10ADD 10612 bytes
SHA-256: ec34e68cd3d04e23bcabf69af158ee76b8c5abdae029cbe516cbbaeac1f23a41
font_01_sfnt_off00012344.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12344 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013b56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B56 17156 bytes
SHA-256: eac74d8a503b2561792aee8fa9658f7c5534a64ce497700fac3c7c793cda38ee