Malicious PDF — malware analysis report

Static analysis result for SHA-256 641fcf0c84232bcb…

MALICIOUS

PDF

91.7 KB Created: 2021-08-20 18:53:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 1637edbfd00599f2ab03c7a0d5f43b4a SHA-1: 068539300bb923e04e60cb4e2f0800fda091ebc3 SHA-256: 641fcf0c84232bcbf8f7de2f617e55338b0926e3e0d83f4cc67172bc44ecb4de
96 Risk Score

Malware Insights

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

The PDF contains a large number of external URIs pointing to compromised WordPress sites, indicating it functions as a link farm. The ML classifier strongly flagged this PDF as malicious, and the presence of numerous links to potentially malicious content suggests an intent to redirect users to phishing pages or download further malware. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://cructi.ru/uplcv?utm_term=how+i+love+thee+song PDF link annotation
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/50e89e99b443adb3a677eaf52f297e42/rogusugar.pdfIn PDF document text
    • https://doitsolutions.co/wp-content/plugins/super-forms/uploads/php/files/c2ceb7b668408d9f9d52a0de2db78934/70933073619.pdfIn PDF document text
    • http://www.zywawiara.pl/pliki/41143510953.pdfIn PDF document text
    • https://www.lightingdynamics.com/wp-content/plugins/super-forms/uploads/php/files/9b2542e1c8bbc04f283b4a2a0736cb1b/wosubaj.pdfIn PDF document text
    • https://plumcourse.com/wp-content/plugins/super-forms/uploads/php/files/5970ac5bc2b9669a2812a3def2280c6e/77880303653.pdfIn PDF document text
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/160bf93a65ee34---45467548585.pdfIn PDF document text
    • https://accounting789.com/ThImg/file/6683444291.pdfIn PDF document text
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/1bbba953652ccb169e73c9194f647bb4/dawilomilo.pdfIn PDF document text
    • http://3qlohas.com/CKEdit/upload/files/vutejanudozumotebomewer.pdfIn PDF document text
    • http://cuatro-pr.org/sites/default/files/file/9878364306.pdfIn PDF document text
    • http://africansafaris-spain.com/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/83902415600.pdfIn PDF document text
    • https://abugfreemind.com/userfiles/file/22201229550.pdfIn PDF document text
    • http://group-anons.ru/userfiles/files/45702593548.pdfIn PDF document text
    • https://areicon.com/images/file/tizon.pdfIn PDF document text
    • https://comobrew.com/newsite/images/user_uploads/file/jawup.pdfIn PDF document text
    • https://christianklein.eu/Quansis/ckfinder/userfiles/files/jajirigafuxibem.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160956157b0d33---21172869145.pdfIn PDF document text
    • https://fullprotec.com/ckfinder/userfiles/files/24053058691.pdfIn PDF document text
    • https://wscnaturalhealings.com/wp-content/plugins/super-forms/uploads/php/files/7432ef1e0c1bb6dd111037b8466c6997/sagusowazogi.pdfIn PDF document text
    • https://massagetheory.ca/wp-content/plugins/super-forms/uploads/php/files/4eb176ca7af391c11347be4dde38b8ee/xexazazokavov.pdfIn PDF document text
    • http://recko.ru/ckfinder/userfiles/files/xevesodovodovovotasosuv.pdfIn PDF document text
    • https://nakipoglugroup.com/upload/ckfinder/files/99511851503.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_off000100b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100B8 18264 bytes
SHA-256: 7c375ebd85600bd26a80071a8860388dbebe3e42956c268f94c36306b2fe935b
font_01_sfnt_off00013094.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13094 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000148ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x148AB 10268 bytes
SHA-256: bc0eb17edaaab04a41b8e169366cc872aabf124fa6fb4d2cbcf4d35d8a34f994