Malicious PDF — malware analysis report

Static analysis result for SHA-256 88797250a432f347…

MALICIOUS

PDF

70.9 KB Created: 2021-09-19 19:25:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: ac1e80b6aded525a5cbeda87f15f5163 SHA-1: 52e9192f867a7b802bcf719da47c73070e5dbd9a SHA-256: 88797250a432f3478d483cd08ec0b306eee7f39c3c16f15ff4ddbd9beec96e63
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged as malicious by ML classifiers and ClamAV. It contains numerous embedded URLs that form a link farm, suggesting a phishing or SEO poisoning attack. The heuristics indicate that the PDF is designed to redirect users to various disposable or compromised hosting sites, likely to distribute further malware or conduct phishing operations. No scripts were extracted, but the structure and URL patterns are indicative of a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • 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.
  • 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://coretry.ru/uplcv?utm_term=general+organic+chemistry+pdf PDF link annotation
    • https://twr1115.net/files/fckeditor/file/defasukiwubafijadaduviwu.pdfIn PDF document text
    • http://85560891.com/upfolder/e/files/20210914165341.pdfIn PDF document text
    • https://twinslock.com/ckfinder/userfiles/files/lunegebuvuzuvu.pdfIn PDF document text
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fffbfbfc35---jumitefaxuxilofuj.pdfIn PDF document text
    • https://ripedesign.com/app/webroot/files/fckeditor/file/54280233239.pdfIn PDF document text
    • http://rnralpha.cz/res/file/52277868211.pdfIn PDF document text
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f6d949201f---88422950808.pdfIn PDF document text
    • http://sziazsauto.com/uploads/files/46612600240.pdfIn PDF document text
    • https://doluhosting.com/calisma2/files/uploads/8976221383.pdfIn PDF document text
    • http://xn--80aaae7amexjfdlfdfg.xn--p1ai/files/file/ravawatijijebuniwunusawe.pdfIn PDF document text
    • https://khmernative-rice.com/userfiles/file/fozikuwujiba.pdfIn PDF document text
    • https://jatransfer.com/userfiles/file/zozaxes.pdfIn PDF document text
    • http://porpora.biz/imagenes/imagenes_contenidos///ragezuv.pdfIn PDF document text
    • https://hitourkorea.com/FileData/ckfinder/files/20210917_E3A10B113E9BCC37.pdfIn PDF document text
    • http://xinyaoqiye.com/upload_fck/file/2021-9-18/20210918091617803664.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/16132d8c1c4500---zupen.pdfIn PDF document text
    • http://koslita.eu/ckfinder/userfiles/files/xobararejitedi.pdfIn PDF document text
    • http://mikailang.com/userfiles/file/20210913040832_2031254365.pdfIn PDF document text
    • http://juncheng.tw/upload/files/92694320086.pdfIn PDF document text
    • http://vnationwide.com/userfiles/files/32157056809.pdfIn PDF document text
    • https://cursosadistanciayonline.com/medios/files/49545490017.pdfIn PDF document text
    • http://kmkonsult.cz/userfiles/file/80948388149.pdfIn PDF document text
    • http://nasfthr.com/userfiles/file/gomamamuwemas.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_off0000b57a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB57A 15432 bytes
SHA-256: 4b58eed72dac3f8c4d35dfd91d2909795890cd7871c28ba523aedf07a026a3ad
font_01_sfnt_off0000dc88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC88 11220 bytes
SHA-256: 2bbf1255ce292e9459c2a4644a701dc5082c536976297212f07e43fbdd1a0cb3
font_02_sfnt_off0000f670.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF670 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1