Malicious PDF — malware analysis report

Static analysis result for SHA-256 a57f9d8ebcf3d98b…

MALICIOUS

PDF

86.6 KB Created: 2021-08-16 00:16:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 07b548376cc1a1b827bc10bf163510fa SHA-1: 2a47c2232107afac84fe3b4c7032c115a0799ae6 SHA-256: a57f9d8ebcf3d98b2dec7a2bf5e5b08c112ec6e2cb1276f8a15f6e7081ba1b9c
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites or disposable hosting, indicative of a link farm designed to lure users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are highly suspicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://pixomot.ru/uplcv?utm_term=addition+and+subtraction+of+decimals+worksheets+grade+5+pdf PDF link annotation
    • http://olgapolyakova.de/files/files/xenobowegokawi.pdfIn PDF document text
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/1608a65483b884---repokojuzagolurusami.pdfIn PDF document text
    • https://marblo.com/app/webroot/img/files/gedanizovoselexite.pdfIn PDF document text
    • http://iberia-ex.com/images/blog//file/vejewagizimakip.pdfIn PDF document text
    • http://slstudio.it/userfiles/files/wowepapudubazomodugegare.pdfIn PDF document text
    • http://best-infosystems.com/userfiles/file/dafawapibezu.pdfIn PDF document text
    • http://www.yemany.com/yemfiles/files/kekipezekuforog.pdfIn PDF document text
    • https://amd-export.com/site/upload/file/zerapekuvuvorubezu.pdfIn PDF document text
    • https://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/f9d12592aca409eec96a29c3776fba32/fexut.pdfIn PDF document text
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607ed2e89b18d---29077695285.pdfIn PDF document text
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160879060d6b44---61291293719.pdfIn PDF document text
    • http://baschin-heizung.com/meineBilderAlbertGrundschule/file/3104548311.pdfIn PDF document text
    • https://apinero.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bf43f4ba0f---57095854441.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/jhooit4m0vp2otpkigvcs5kkf5/56983157951.pdfIn PDF document text
    • http://automsystem.com/UploadFile/file/20210618075052451.pdfIn PDF document text
    • http://les-dvorik.ru/userfiles/file/81564589934.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/d8335191425f90ca1c619b27cc4cdd85/fakitad.pdfIn PDF document text
    • http://peggylittlelawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/rifanijipuxomazelelaw.pdfIn PDF document text
    • http://ankurgroups.com/userfiles/file/jabusegubagowutele.pdfIn PDF document text
    • http://agriturismocorteerbatici.it/userfiles/files/15135955425.pdfIn PDF document text
    • 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_off0000ec0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC0E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010425.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10425 11600 bytes
SHA-256: eafda3b451080f5447a7dd310ca7dda3e3a07bb9f14f91c06b5534d64fe86435
font_02_sfnt_off00011f3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F3D 16936 bytes
SHA-256: 2a2e041468a198fc174cb60665ea2321780ac6891ccb754ce3cd161f1a03aa00