Malicious PDF — malware analysis report

Static analysis result for SHA-256 c675566427bd9ff2…

MALICIOUS

PDF

81.9 KB Created: 2021-08-19 05:15:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 242d7d980e0249b6620f86d1d3ac8a2e SHA-1: 582a529f454e19113baaaca87b68e85551244368 SHA-256: c675566427bd9ff2323efb6231d53a2b9c22ebe33fcaa00829ada71d4604f372
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to other PDF files, many hosted on compromised WordPress sites or disposable domains. The ML classifier strongly indicated maliciousness, and the heuristic firings suggest this is a link farm designed to manipulate search engine results or distribute further malicious content. No scripts were extracted, but the presence of multiple external links is a strong indicator of malicious intent.

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 https://cructi.ru/uplcv?utm_term=how+to+use+a+cen-tech+digital+clamp+multimeter PDF link annotation
    • http://giga.sk/storage/file/77290861980.pdfIn PDF document text
    • http://bettaletroom.com/file_media/file_image/file/92368329733.pdfIn PDF document text
    • http://www.bash.cl/media/file/29785646006.pdfIn PDF document text
    • http://amuseonline.com/absite/userfiles/file/rovumavobetotakimirapij.pdfIn PDF document text
    • https://bonvoyageindia.in/ckfinder/userfiles/files/15114682368.pdfIn PDF document text
    • http://khanaphatgroup.com/UserFiles/file/xamujorasamiginifev.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/160956dfce7ac2---42917757021.pdfIn PDF document text
    • http://iideree.org/wp-content/plugins/formcraft/file-upload/server/content/files/160ab7e09a3bfc---sateginolofebuwogox.pdfIn PDF document text
    • http://www.meglobalinc.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160b9f44e9d570---sifuk.pdfIn PDF document text
    • http://drkoopman.nl/cmsimages/file/nijasufe.pdfIn PDF document text
    • http://stylist.in.ua/wp-content/plugins/formcraft/file-upload/server/content/files/160873029db31d---98929040542.pdfIn PDF document text
    • https://fajndoktor.cz/images/file/files/38142471851.pdfIn PDF document text
    • https://bustotoronto.com/userfiles/file/sirusoxudobimeju.pdfIn PDF document text
    • http://debsluxe.com/clients/1/17/174397649ed9f07baa8f9d9f48c72a4d/File/kumemifivuti.pdfIn PDF document text
    • http://ar-intl.net/wp-content/plugins/super-forms/uploads/php/files/g0e24967cfnn1md7cg0ohdgn55/mifaragaxewogiti.pdfIn PDF document text
    • https://hoovermaids.com/wp-content/plugins/super-forms/uploads/php/files/cb510f6082cae295c5b2d7b0914fff4a/negatigafutozedabu.pdfIn PDF document text
    • http://krukewittfarms.com/userfiles/file/87340321810.pdfIn PDF document text
    • https://travelworld.ro/userfiles/file/95237302519.pdfIn PDF document text
    • http://anhuishangbiao.com/upload_fck/file/2021-5-10/20210510111353158197.pdfIn PDF document text
    • https://technok.cz/wp-content/plugins/super-forms/uploads/php/files/5e9ebe1aa15f67fa9a5c49043c7f8a8b/44860670278.pdfIn PDF document text
    • http://apexibd.com/uploads/fck_uploads/file/2132531312.pdfIn PDF document text
    • https://www.idromeccanicasrl.com/idromeccanicasrl.com/wp-content/plugins/super-forms/uploads/php/files/1fa7ef997573ce39a198e0889b146cd1/60101934512.pdfIn PDF document text
    • http://savvyais.com/userfiles/file/ligidiwijuni.pdfIn PDF document text
    • http://www.cenlajobinator.com/siteuploads/editorimg/file/dovenagadaxesimiratipu.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_off0000ddbb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDBB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f5cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5CD 16292 bytes
SHA-256: b0ae4fbe9923f012cf1fdffd5b5ed46b21c5463d2e35fa7b15aba71cf43de565
font_02_sfnt_off00011ff3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FF3 11172 bytes
SHA-256: 116f2facf673bfdb3524b8d12c55e0f28a69365d517e9c419fa543adad834993