Malicious PDF — malware analysis report

Static analysis result for SHA-256 39666737ddfda1af…

MALICIOUS

PDF

90.4 KB Created: 2021-09-03 07:59:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: 54edd4ee8f190557cd6a22af52a5efd3 SHA-1: 0b2a2126f492d51eec05e2d760834693e90afe1f SHA-256: 39666737ddfda1af4e343b7f86a0074fb6f424e7b0436d0299ee339262251b4e
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.5191

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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/ff35579cdfb543c3133d135e0151fe2d/fefadaf.pdf In PDF document text
    • http://bright-mineral.com/uploadfile/file/2021072606073641.pdfIn PDF document text
    • http://chongthamnguoc.vn/img/files/lezutuxupoloxofemowuloxo.pdfIn PDF document text
    • http://clair-environnement.eu/catalogue_dynamique/file/wovofokawuma.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16075cb89f3748---posakad.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609847f6ab7c2---77943435137.pdfIn PDF document text
    • http://tavernadelsnoguers.com/wp-content/plugins/super-forms/uploads/php/files/8b31550fde686861288b8334d29e8fc8/dafajapenivenixadonivote.pdfIn PDF document text
    • https://rittenhousesmiles.com/wp-content/plugins/super-forms/uploads/php/files/e1c63d2a978c103fff8ed989610da5b5/nuzazinunibajila.pdfIn PDF document text
    • http://traiteur-ribot.fr/userfiles/file/felobobojazi.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16094d534184fb---22982783754.pdfIn PDF document text
    • https://canvasations.com/wp-content/plugins/super-forms/uploads/php/files/1qukqr50531vkp3qgon0ksmsc7/95274070203.pdfIn PDF document text
    • https://catbasailing.com/upload/fck/file/kagozuxikupusekurawob.pdfIn PDF document text
    • http://www.dj-csnl.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160bd0d1c758aa---72116050924.pdfIn PDF document text
    • http://bruisedreedfoundation.org/clients/4/4d/4d9d7eec3bf3a09fa0457ace138f6a4e/File/sadidiguzinukes.pdfIn PDF document text
    • https://asigurareingermania.ro/wp-content/plugins/super-forms/uploads/php/files/g56l522ubt659avk5in9j7gq4m/nugotu.pdfIn PDF document text
    • http://myagreement.com/UserFiles/file/fobidakemamu.pdfIn PDF document text
    • http://gavinlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/80531655188.pdfIn PDF document text
    • http://www.thaitofu.com/image/upload/File/dekikif.pdfIn PDF document text
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/32b75498af98c0399c16b9560981c868/97842122851.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/160b2b7cb59c9e---27212513286.pdfIn PDF document text
    • http://kiuanai.com/userfiles/file/89923935720.pdfIn PDF document text
    • https://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/93ee3e8792c764cb81b4b489969359a3/tawatigigukudusefedap.pdfIn PDF document text
    • http://ttlh.vn/storage/ckfinder/files/68675797042.pdfIn PDF document text
    • http://sapaethnic.com/webroot/img/files/vupufeporuvejuwasirito.pdfIn PDF document text
    • http://msamerica.net/clients/873634/File/gibolen.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=pub+quiz+picture+round+pdfPDF link annotation
    • 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_off0001090b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1090B 10684 bytes
SHA-256: 59c050db008ee9342b0ba208d2aafd714d429fc4f33f2b7efa5ce67fefcbfacd
font_01_sfnt_off0001213f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1213F 18636 bytes
SHA-256: ab6e1a2a15c23aa0dc2819a89bb9cf45eb0c7c8fe82bf1f9c618e6abe0217e54
font_02_sfnt_off000151cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x151CD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1