Malicious PDF — malware analysis report

Static analysis result for SHA-256 f7995a310a9d6314…

MALICIOUS

PDF

86.0 KB Created: 2021-09-21 04:54:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: c2f5cba8c91329aeb684ead0160d5fda SHA-1: 2a50abe874eb00f3660e392aff406b6cb34a25c0 SHA-256: f7995a310a9d63147525e94a3c5ab9882b5b4d60df1de89d4942e0705a8afa81
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or are part of link farms on disposable hosting. The ML classifier strongly indicated maliciousness. While no scripts were extracted, the structure and URL distribution suggest a malicious intent to redirect users, potentially for SEO spam or to lead them to further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://recviem.ru/img/upload/56941444777.pdf In PDF document text
    • https://artedelvalle.cl/gal/files/file/19397547641.pdfIn PDF document text
    • https://kachhiproperties.com/wp-content/plugins/super-forms/uploads/php/files/d7c635bac565f4957d5a3c6c58e0ac1b/94744745297.pdfIn PDF document text
    • https://locoffice.ru/userfiles/file/11806437290.pdfIn PDF document text
    • http://savaksangida.com/resimler/files/29234666615.pdfIn PDF document text
    • http://zxpgw.com/userfiles/file/jesematabafowabajavaka.pdfIn PDF document text
    • http://toanthinh.vn/webroot/img/files/mabotoviwuxe.pdfIn PDF document text
    • http://vinhthuan.vn/upload/files/82420660219.pdfIn PDF document text
    • http://jamalcar.com/userfiles/file/totataxegitiladeku.pdfIn PDF document text
    • https://botroul.be/uploads/74863126531.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/od80il1rkpn8lo6tbk31m52n87/21154195977.pdfIn PDF document text
    • https://jakspravnenapsa.cz/userfiles/file/jizasigowuwek.pdfIn PDF document text
    • https://patidarpalanpur.com/web/k/main_admin/ckfinder/userfiles/files/difusaratulofatogovakeb.pdfIn PDF document text
    • http://www.rify.us/cms-uploads/files/guvakipofezimojusepixada.pdfIn PDF document text
    • http://hnhappiness.com/d/files/15415153287.pdfIn PDF document text
    • http://lpsa.cz/userfiles/file/tedelufiwojinofanusevus.pdfIn PDF document text
    • http://neboskreb-irk.ru/uploads/userfiles/files/78789913220.pdfIn PDF document text
    • https://www.domaine-boussard-chablis.fr/ckfinder/userfiles/files/56910171513.pdfIn PDF document text
    • https://esperidiaogomes.com/userfiles/files/puzekugikigeburazekubidu.pdfIn PDF document text
    • http://urparitet.ru/admin/ckfinder/userfiles/files/konigawubipeloribasitemor.pdfIn PDF document text
    • http://thuocamakong.net/userfiles/image/file/zavenoz.pdfIn PDF document text
    • http://www.gonouvellezelande.com/files/51953742614.pdfIn PDF document text
    • https://www.marbelitesa.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1612feea28424f---87017405509.pdfIn PDF document text
    • https://www.ijdsir.com/ckfinder/userfiles/files/dutawuliseda.pdfIn PDF document text
    • http://zeshengtecphar.com/UploadFiles/FCKeditor/20210905114336.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=free+warzone+cp+pointsPDF 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_off0000e8f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8F6 10444 bytes
SHA-256: 55da98fffebf90e6ad4d4e9da89e50a3efa985a484a6ada6f75c70f013a5dae3
font_01_sfnt_off000100e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100E1 18792 bytes
SHA-256: 1cfdfcc5f28c97d3270a3c5593a86414dcc7cf759b84a39f51d5ab3e5831b7c6
font_02_sfnt_off0001320c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1320C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1