Malicious PDF — malware analysis report

Static analysis result for SHA-256 0a455a0fc0ad5892…

MALICIOUS

PDF

74.3 KB Created: 2021-09-03 07:50:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: bffc7b7af2e8cb17fab18e6fd2209fe7 SHA-1: d85c1c04ea1a3e3fd43eb72bd2de69ef491de165 SHA-256: 0a455a0fc0ad589253be0b1f937810f8f39999793a8ac3adddac5916f8acc345
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to other PDF files hosted on various domains, suggesting a link farm or redirection mechanism. The ML classifier strongly flagged this PDF as malicious, and heuristics indicate it's part of a link farm on disposable hosting, potentially for SEO poisoning or distributing further malware. The presence of compromised CMS upload links further supports malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9914

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://medvor.ru/uplcv?utm_term=mcdougal+littell+grammar+for+writing+workbook+grade+8+pdf PDF link annotation
    • http://poaglasses.com/uploads/files/202108142102156802.pdfIn PDF document text
    • https://bursac.net/userfiles/file/dulanojoxurigifagozo.pdfIn PDF document text
    • https://mytutr.com/wp-content/plugins/super-forms/uploads/php/files/ccc92d722182145bfb4f7f09338239bb/bojikesisukivos.pdfIn PDF document text
    • http://kirakuramen.com/uploads/files/pumosuvokateva.pdfIn PDF document text
    • http://dinhviht.com/images/newtech/files/funofudatevuli.pdfIn PDF document text
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/8295597f3bcfc054eadfaf2adfb3e50a/2463803783.pdfIn PDF document text
    • http://aqs-group.it/userfiles/files/xewupuvepemipur.pdfIn PDF document text
    • https://cornwallstaffagency.com/userfiles/file/bomasuzexamowazagebixomem.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160ab7b6ed4da7---93599938532.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8cc6c2c31---40091755090.pdfIn PDF document text
    • http://relocationservicesgroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606da6eb89856---98504785988.pdfIn PDF document text
    • https://hafa-verein.de/wp-content/plugins/super-forms/uploads/php/files/610d6a5df8ee85df91f46c82dcee4b1d/94944957390.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160925c28056e3.pdfIn PDF document text
    • https://magazinul-de-instalatii-sanitare.ro/app/webroot/files/userfiles/files/62571970763.pdfIn PDF document text
    • https://binarbaid.com/public_html/userfiles/file/60896209186.pdfIn PDF document text
    • http://businessplan-capalpha.fr/mbp/upload/images/images/upload/ckfinder/rodenifixopisamir.pdfIn PDF document text
    • http://clinicacomciencia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b13bed2abf0---digofazobovozuwatuku.pdfIn PDF document text
    • https://sipsib.ru/wp-content/plugins/super-forms/uploads/php/files/dcbc035f97596dff4e6f0ddc264d902e/32789627532.pdfIn PDF document text
    • http://se-ty.ru/uploads/userfiles/file/falig.pdfIn PDF document text
    • https://khogiaydantuonghanquoc.com/images/news/file/zawotapata.pdfIn PDF document text
    • https://grafitpoint.ru/wp-content/plugins/super-forms/uploads/php/files/1f3cff0adcdcc737522192e1039e684c/30280840296.pdfIn PDF document text
    • http://www.jcca.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/1607452e86c4b2---64604295229.pdfIn PDF document text
    • https://spa-salon.ru/ckfinder/userfiles/files/detexuti.pdfIn PDF document text
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/f8f825d27fbc01e216339a9196304ae3/5501026583.pdfIn PDF document text
    • http://www.putnamtaxi.net/wp-content/plugins/formcraft/file-upload/server/content/files/160baede047218---rumevareguwodev.pdfIn PDF document text
    • http://sbairs.com/datas/files/95687175082.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_off0000bd8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD8D 11416 bytes
SHA-256: f3c899594005a2d1aeebdb8e5f1d2694813c1b6065a9f055067b92e223f97e88
font_01_sfnt_off0000d828.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD828 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f03a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF03A 16460 bytes
SHA-256: 7bec991b08825ef02e5cba0b0ab0f007a9b1ab4476f90754bacd4362646a7e8e