Malicious PDF — malware analysis report

Static analysis result for SHA-256 0a9668fef453754e…

MALICIOUS

PDF

72.1 KB Created: 2021-09-28 17:30:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 4084c8be3382092c6a195698e9188348 SHA-1: 4e6a75dad5f91a78cbcd89fd0a460452424ef02a SHA-256: 0a9668fef453754edf1ef4228795646d5eb9f346661398dad7fb2bbb56a5696b
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious. While no scripts were directly extracted, the nature of the embedded links suggests a phishing or malware distribution attempt, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • 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://inwebjor.ru/uplcv?utm_term=download+cake+learn+english PDF link annotation
    • http://penzionnakrizankach.cz/ckfinder/userfiles/files/fulujerofivipafedopus.pdfIn PDF document text
    • https://moulindelarroque.com/userfiles/file/vavifizugud.pdfIn PDF document text
    • http://eyupsifalibitkiler.com/resimler/files/sujurevajozotitodododosel.pdfIn PDF document text
    • https://soi.icami.mx/ckfinder/userfiles/files/vugupulosurimovesota.pdfIn PDF document text
    • http://cornucopiafrederick.com/uploads/files/49455086635.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16147759d92c08---sofosuvawuva.pdfIn PDF document text
    • https://gikguamerica.com/userfiles/file/zitowotixikofixodu.pdfIn PDF document text
    • https://ibexquimica.com.br/ckfinder/userfiles/files/55875545358.pdfIn PDF document text
    • https://hssanesteban.cl/files/27067332824.pdfIn PDF document text
    • http://angarakshaksecurity.com/userfiles/file/14370232889.pdfIn PDF document text
    • http://savvyais.com/userfiles/file/jujufasibanamizila.pdfIn PDF document text
    • http://msnladyboy.com/ckfinder/userfiles/files/bugexenexege.pdfIn PDF document text
    • https://fond.ru/userfiles/file/70993337897.pdfIn PDF document text
    • https://sukienmiennam.com/userupload/files/75734891167.pdfIn PDF document text
    • http://aibasylhet.edu.bd/app/webroot/ckfinder/userfiles/files/sokajenewijapawej.pdfIn PDF document text
    • http://e-motyle.natura2000.pl/imgturysta/files/76193531978.pdfIn PDF document text
    • http://avtrak.ru/ckfinder/userfiles/files/31324923579.pdfIn PDF document text
    • https://sunsetlearningcenter.com/userfiles/file/24840432231.pdfIn PDF document text
    • http://bodemveenweiden.nl/bodem-veenweiden-img/navoxikujesokexaseguzupe.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161409024a3322---50576753090.pdfIn PDF document text
    • http://chi-kara.net/Upload/files/12081071657.pdfIn PDF document text
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1613825359a71a---77962262290.pdfIn PDF document text
    • http://letsfinal.com/userfiles/file/xumiritadotemivijuwuju.pdfIn PDF document text
    • http://st-ark.it/userfiles/files/55585286978.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_off0000b4a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4A8 10728 bytes
SHA-256: aa53c28a749052405dd038c88c1106e69d6792ffeade8f92b6926292cd65e635
font_01_sfnt_off0000cd0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD0E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e520.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE520 17660 bytes
SHA-256: 8a5dfc928c9a8a04c5de8539dd7eb962b298271c6496ec600a12ebf080d5113a