Malicious PDF — malware analysis report

Static analysis result for SHA-256 f51a99818256675f…

MALICIOUS

PDF

69.9 KB Created: 2021-09-02 20:02:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 709940d4e4aa0a985a964bf7128d46f5 SHA-1: 9edafb88159998a47ff31421eca42880f0aa5bf6 SHA-256: f51a99818256675f887146d1f93fe456f508667cc007bb67203c9bddc1555e81
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites and are structured as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for SEO manipulation or to direct users to phishing or malware distribution sites. The presence of multiple compromised CMS upload links further supports this. No scripts were extracted, and the document body was unreadable.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 http://chapmanhighschoolclassof1968.com/clients/c/cb/cb1fed5110c07f199f416a264ee6943c/File/jupekosi.pdf In PDF document text
    • http://fuzoku-kyujin.jp/ckfinder/userfiles/files/xaloluxaxetikekisududupow.pdfIn PDF document text
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607dfd869f28d---tabekasugurikezi.pdfIn PDF document text
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084b158601ec---nawudikojaxe.pdfIn PDF document text
    • http://yeongwonenc.com/userfiles/file/kesokenetowagu.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/1608501f4a1940---42743154726.pdfIn PDF document text
    • http://principessavencanice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab69aab62e9---99987711874.pdfIn PDF document text
    • https://zazilha.com.mx/wp-content/plugins/super-forms/uploads/php/files/f018a54a0dca83b64bf5e29df7a9572d/kupaketifeza.pdfIn PDF document text
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/160d4a835b5d38---koropodoke.pdfIn PDF document text
    • http://amblesidewindermere.ca/fckuploads/images/file/giturozid.pdfIn PDF document text
    • http://dges.in/userfiles/file/xegazomo.pdfIn PDF document text
    • https://qualitymattressfactory.com/admin/userfiles/file/tefesolapotem.pdfIn PDF document text
    • http://aygroupmuh.com/image/files/lapuji.pdfIn PDF document text
    • http://say-international.eu/userfiles/file/32097645780.pdfIn PDF document text
    • http://vititanon.com/user_img/files/vosotunefemem.pdfIn PDF document text
    • http://www.socalgreatwhite.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a772fe6b0f---64268372552.pdfIn PDF document text
    • https://krimgranit.ru/wp-content/plugins/super-forms/uploads/php/files/20c98f2cb8ff18c0850003fa9253a1af/tuxaminexuponoru.pdfIn PDF document text
    • http://www.vegagastro.pl/upload/file/jekifujolipabis.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/74bf03734d29b219419ea9fc1dcb56da/murifugatuwosotibol.pdfIn PDF document text
    • https://simovi.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160d192b825a65---16237407221.pdfIn PDF document text
    • https://ludifrance.fr/userfiles/file/59095941268.pdfIn PDF document text
    • http://panyuchen.com/ckfinder/userfiles/site_eachfun_com/files/waromov.pdfIn PDF document text
    • http://frutapacargentina.com/ckfinder/userfiles/files/lotudason.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/74930889204.pdfIn PDF document text
    • https://www.studioline.ie/ckfinder/userfiles/files/woresavagidunupevupirunor.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=list+of+soluble+fiber+foods+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_off0000b544.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB544 14980 bytes
SHA-256: cd5f5d261eb741e5c4e77280c2af5d4d4721c19456f19b31b26365bf95ab756b
font_01_sfnt_off0000daa4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAA4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f2bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2BB 10420 bytes
SHA-256: bf32834eae0e804eefde32fdcac8e3af2727ee080a9e310973b203e42d5ac2cd