Malicious PDF — malware analysis report

Static analysis result for SHA-256 77cf834153b501a2…

MALICIOUS

PDF

82.7 KB Created: 2021-09-17 13:13:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 30088ceda0456051e5ddd922af3154d5 SHA-1: 2d234795088b80e204b4739dba62aabe044dbc22 SHA-256: 77cf834153b501a2233fdaacedc60482e70aeae719f29a6db17923542e97092a
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that point to various domains, many of which are hosted on compromised or disposable infrastructure. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using link farms on disposable hosting, suggesting an attempt to obscure the final malicious destination. The ML classifier strongly flags this PDF as malicious, supporting the conclusion that it is designed to redirect users to harmful 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 https://irlanc.ru/uplcv?utm_term=dangerous+to+know+and+love+pdf PDF link annotation
    • http://plkorea77.com/ckupload/files/nozejex.pdfIn PDF document text
    • http://dxqzx.com/ckfinder/userfiles/files/20210916_225919.pdfIn PDF document text
    • https://weishinclinic.com/uploads/files/202109051738363672.pdfIn PDF document text
    • http://uat2.hkha.com.hk/ckfinder/userfiles/files/gexudojaxinof.pdfIn PDF document text
    • http://panda-es.tokyo/yamituki-n/uploads/files/xerawitadag.pdfIn PDF document text
    • https://cliniquemyo.com/userfiles/file/suwusomilixezekafexe.pdfIn PDF document text
    • http://metalltechnik-kutschi.at/41730014701.pdfIn PDF document text
    • http://raduzhniy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142a525d717d---44906484461.pdfIn PDF document text
    • http://studiorestagno.eu/userfiles/files/pibewijerevokijuvu.pdfIn PDF document text
    • http://gsmontaggi.it/userfiles/files/xaxotasutaruv.pdfIn PDF document text
    • https://saksisan.com/upload/ckfinder/files/54734750013.pdfIn PDF document text
    • http://gavionescodeinsa.com/userfiles/ruxagegemesujixodemakabor.pdfIn PDF document text
    • http://majstrissmt.eu/www-data/file/nopozawixi.pdfIn PDF document text
    • https://www.autopsrus.com/ckfinder/userfiles/files/butufokakenolibix.pdfIn PDF document text
    • http://imdad-egypt.com/userfiles/file/lofalarogeta.pdfIn PDF document text
    • http://orem.mn/uploads/files/63189241180.pdfIn PDF document text
    • https://xn--80adj7cxa.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/d34b974994e414e57cbf6aa2ef11d4c0/peborasibidizuzajenexe.pdfIn PDF document text
    • https://homeaestheticsllc.com/wp-content/plugins/super-forms/uploads/php/files/ad379b68c4cb2e1b280e3a5c53cca231/zeromajugasezaturapeli.pdfIn PDF document text
    • http://menifee.hanasushichoice.com/uploads/files/javabifege.pdfIn PDF document text
    • http://thaicockstar.com/ckfinder/userfiles/files/83276535466.pdfIn PDF document text
    • http://rowadhr.com/app/webroot/upload/files/64059575065.pdfIn PDF document text
    • https://defi128.phpascal.com/userfiles/files/pipidosiwoferosigutiv.pdfIn PDF document text
    • http://pandoraecza.com/genelresimler/file/parabejugutusogedipagusib.pdfIn PDF document text
    • http://wmsone.com/eimages/file/semazanananiti.pdfIn PDF document text
    • http://www.vandiestbrandstoffen.be/uploads/files/60163875444.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_off0000dc3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC3D 10924 bytes
SHA-256: fe1d5ee41cd6454b615e763a2fb0bedb1a70e8073ee0bed84a34b6cf649b96c6
font_01_sfnt_off0000f59a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF59A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010dac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DAC 18420 bytes
SHA-256: 7c38303dcd7733ed59ac67af6bdefed0294b22c2e5f07e0350ffe37185c214cb