Malicious PDF — malware analysis report

Static analysis result for SHA-256 51590b40466c0943…

MALICIOUS

PDF

80.9 KB Created: 2021-09-01 13:48:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 25f725a62fbd88e7d17e8c03274f3209 SHA-1: 34ff153294a5a26c0952e4844d31a937daa80c56 SHA-256: 51590b40466c0943459b924abe713cd094e7b79962ceb36fbaf04cd10c18034a
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous links pointing to potentially compromised or disposable hosting sites, indicative of a link farm used for phishing or malware distribution. The ClamAV detection and ML classifier strongly suggest malicious intent. The embedded JavaScript likely facilitates the redirection to these malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://schnauzermountainminiatures.com/clients/17729/File/forovagosopuxekadanaza.pdf In PDF document text
    • http://stadion-zarya.ru/ckfinder/userfiles/files/jisagiluzadovim.pdfIn PDF document text
    • http://jiehuist.com/userfiles/files/1724900122.pdfIn PDF document text
    • http://freehajjandumrah.com/admin/admin/uploadfiles/file/84502649184.pdfIn PDF document text
    • https://12shio4.com/contents//files/71291231102.pdfIn PDF document text
    • https://blokhol.com/upload/files/nonulos.pdfIn PDF document text
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1609d47421ff1e---55192543369.pdfIn PDF document text
    • http://djpress.pl/Image/files/vejabegopived.pdfIn PDF document text
    • http://scoopsites.net/userfiles/file/46446444954.pdfIn PDF document text
    • https://lightspec.com/wp-content/plugins/super-forms/uploads/php/files/836bf155f0c50ce689c21bff08389d0a/23072328863.pdfIn PDF document text
    • https://fa-vietnam.com/webroot/img/files/ralubumizarijaxirifosoza.pdfIn PDF document text
    • https://envomask.com/wp-content/plugins/super-forms/uploads/php/files/54bad71030d5f98fcb9057db620c716c/wimikefojelurudufejov.pdfIn PDF document text
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160845bc5c1ec0---rojefowolamil.pdfIn PDF document text
    • https://win-win-keiba.site/js/ckfinder/userfiles/files/zexipogizugapovuxad.pdfIn PDF document text
    • https://www.kiakaha.gr/wp-content/plugins/super-forms/uploads/php/files/sv7lbkb86d5llpiinurihidm0j/39958991602.pdfIn PDF document text
    • http://nct-vn.com/userfiles/file/gokosugo.pdfIn PDF document text
    • http://www.platformliften.info/wp-content/plugins/formcraft/file-upload/server/content/files/16094aa68e9277---53878146777.pdfIn PDF document text
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad823a2fd1c---bakexidepizepap.pdfIn PDF document text
    • http://connect-senior.ch/uploades/userfiles/file/zibafuk.pdfIn PDF document text
    • http://gdwtechnology.com/fckeditor/file/55568305833.pdfIn PDF document text
    • http://rotarylaspalmas.orgdocumentos/file/jupadafabodalosu.pdfIn PDF document text
    • https://eyetracking.pl/userfiles/file/sivobodomabu.pdfIn PDF document text
    • http://jatyn.cn/upfiles/202105/file/1621154967.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=contractual+terms+meaningPDF 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_off0000d628.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD628 17304 bytes
SHA-256: 2dc16508d1f91d832f85b10ef3e5192e01de6b1f76a5e43a6ca4745cdb73480e
font_01_sfnt_off000102e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102E7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011afe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AFE 10704 bytes
SHA-256: a2dfd9a44c5d92e8cdd331b71490c61ace8dc4118a968c41b2f21020541457d2