Malicious PDF — malware analysis report

Static analysis result for SHA-256 93a65c250db75371…

MALICIOUS

PDF

88.3 KB Created: 2021-09-09 19:36:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 96808fcdd7a71782acdc5ea41662e50b SHA-1: 7fe4659bbd8b24095789959aa4b7721537cb078e SHA-256: 93a65c250db753714139182b7d75a3fe48ef772bb3c9502945e8bc4cd329f6de
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. The PDF contains numerous links to external PDFs hosted on various domains, with a significant number of these domains appearing disposable and used for link farming. One such link points to 'http://insureavisitor.com/userfiles/file/josufilavabomuva.pdf', which is a strong indicator of a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://insureavisitor.com/userfiles/file/josufilavabomuva.pdf In PDF document text
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16139bcc9b4196---20726962826.pdfIn PDF document text
    • http://way-of-spirit.ru/upload/file/gubawi.pdfIn PDF document text
    • http://giteduguedesboires.fr/userfiles/file/92041811536.pdfIn PDF document text
    • http://www.buildonhope.org/file/42430681410.pdfIn PDF document text
    • http://hillsclinic.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/mamiduniwikexusowin.pdfIn PDF document text
    • https://liepasmuiza.lv/userfiles/library/5835076526.pdfIn PDF document text
    • http://iccjsc.vn/images/uploads/files/75233784451.pdfIn PDF document text
    • https://www.habitat-morvan.fr/ckfinder/userfiles/files/tumotokakip.pdfIn PDF document text
    • http://studiofagiani.eu/userfiles/files/maraji.pdfIn PDF document text
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132c9e20b07c---gozoworewikosamonigeg.pdfIn PDF document text
    • http://meadescafe.com/userfiles/file/dulalefugaveg.pdfIn PDF document text
    • http://gintaras.cz/userfiles/file/1133985243.pdfIn PDF document text
    • https://matras-matrasych96.ru/admin/ckfinder/userfiles/files/75133838976.pdfIn PDF document text
    • http://lawngo.net/fckfiles/10048085826.pdfIn PDF document text
    • http://klusjesindex.nl/images/uploads/621122669.pdfIn PDF document text
    • https://www.sonorisation-auxerre.fr/ckfinder/userfiles/files/zusutowilewomimedav.pdfIn PDF document text
    • http://htygroup.com/upload/files/99675285251.pdfIn PDF document text
    • https://eletvital.hu/uploads/files/nosomifirorene.pdfIn PDF document text
    • http://ybshajiang.com/userfiles/file/2021-09-06/210906235432595889vlz7sae8yxhe.pdfIn PDF document text
    • https://karpataljaturizmus.hu/upload/52123209764.pdfIn PDF document text
    • https://ms01bet.net/contents/files/xaguvagapus.pdfIn PDF document text
    • http://fuhua.tumujike.com/assets/upload/files/202109030016595234.pdfIn PDF document text
    • http://xedaptheduc.net/app/webroot/uploads/files/wewifipedufidu.pdfIn PDF document text
    • https://lanna-flyingclub.com/ckfinder/userfiles/files/44092473825.pdfIn PDF document text
    • http://jyjwqj.com/uploadfile/file///2021090601481853.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=keywords+everywhere+chrome+extension+alternativePDF 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_off0000f245.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF245 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010a57.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A57 18340 bytes
SHA-256: ce7d08d8e77557b65249017c81f8bab3fee83b60340c852d0559eba8e0e99208
font_02_sfnt_off000139f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x139F3 10996 bytes
SHA-256: 0b392a4e4b7a32c3a52a060ac8bc28a4909bdc0d62d6e7edaf5ed30a36abc0fc