Malicious PDF — malware analysis report

Static analysis result for SHA-256 52a16bd449e1f4b1…

MALICIOUS

PDF

78.1 KB Created: 2021-07-25 08:49:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: ebf02f8913587a36a6501d2d40e38b9b SHA-1: 9ed23308584ac5aef0c70268d3f394ae868d6d3f SHA-256: 52a16bd449e1f4b11caba9c061e4e105100fed09dfc297c7b53ffbefb8a95b2f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It contains numerous links pointing to compromised WordPress upload directories and other disposable hosting, suggesting a link farm designed to redirect users to malicious content. The PDF structure and embedded links indicate an attempt to exploit users by directing them to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • 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.
  • 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://bikeid.net/ckfinder/userfiles/files/46853693222.pdf In PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c301745995d---surukijog.pdfIn PDF document text
    • http://www.fullertherapy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608574c1e8490---gerone.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c74300027e---gifisawa.pdfIn PDF document text
    • http://architettoannalisatinelli.it/userfiles/files/pimixikepa.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/160d3e4f2c1714---nixafunumekakulilazajor.pdfIn PDF document text
    • https://stcc-sa.com/motakamel/Ups/files/89564935851.pdfIn PDF document text
    • http://transporteslaplata.com/imagenes_web/file/wofapafiwaxeriv.pdfIn PDF document text
    • https://alshamiltrading.com/alshamilfiles/file/75930145617.pdfIn PDF document text
    • https://peiitw.com/Upload/ckeditor/files/32424956798.pdfIn PDF document text
    • http://mstreatmentadvances.com/userfiles/files/durepironifusisa.pdfIn PDF document text
    • https://www.tonygssoulfood.com/wp-content/plugins/super-forms/uploads/php/files/ea36793321641acda28dfbf77daf4236/58652145416.pdfIn PDF document text
    • http://platcometals.com/images/file/12886714617.pdfIn PDF document text
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606ff3c18ea04---zalaleza.pdfIn PDF document text
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d7e4a19b598---40386541007.pdfIn PDF document text
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b6584636a12---68692263780.pdfIn PDF document text
    • https://bamfieldrental.com/userfiles/file/92555977492.pdfIn PDF document text
    • http://stepasidemedical.com/images/uploads/file/pobubizefobipidasateduse.pdfIn PDF document text
    • http://gildiamasterov.ru/userfiles/file/78881425305.pdfIn PDF document text
    • https://travelstore.tn/userfiles/file/96776435384.pdfIn PDF document text
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/3jrt8e3een21mttat4ci1d63r4/60404605844.pdfIn PDF document text
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/264488a445c011c5d7897b1a6bdcfdc7/xerakovewewi.pdfIn PDF document text
    • https://nscs.org/wp-content/plugins/super-forms/uploads/php/files/0567625d10c498c3a4c4be4567dc552b/60790470671.pdfIn PDF document text
    • http://chatsworth72.com/clients/5/53/532ec3c8dc0e95779814939736d4df6d/File/97885604639.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=problemas+matematicos+segundo+de+primaria+para+imprimirPDF 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_off0000cc91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC91 16784 bytes
SHA-256: 28ebe7177d92f291d1d79f0143249a68b1c9e856bc88bad35265b7b726dc033f
font_01_sfnt_off0000f6dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6DC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010ef3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EF3 11096 bytes
SHA-256: e69d8473b4d5276c2e6a70f61602e836464afabbaab58b76203cea89dcbe167d