Malicious PDF — malware analysis report

Static analysis result for SHA-256 63afab23eaf4c9e6…

MALICIOUS

PDF

77.6 KB Created: 2021-09-01 06:05:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: f9a7b14fd364c9f9c373e1afbf48ec90 SHA-1: 197565acf23ed25320decd2b1e4dc048bb1b135e SHA-256: 63afab23eaf4c9e6924ae45dca14f3b014e2865aff4a908cba5b32844e931e26
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf, rather than user-facing text.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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 http://duef.ru/public/file/pepivilej.pdf In PDF document text
    • https://betenrealestate.com/sites/default/files/file/wogewogesupesuseforabezer.pdfIn PDF document text
    • http://xn--80aaaaaikdebj9ccf1ayja1b5a3q.xn--p1ai/ckfinder/userfiles/files/40298030326.pdfIn PDF document text
    • http://alfavit.tv/userfiles/file/logeledekavemupakebes.pdfIn PDF document text
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa6a4cd50d0---pazasapevipogupigazotegi.pdfIn PDF document text
    • https://chefinhogourmet.com/wp-content/plugins/super-forms/uploads/php/files/ea1901b81fd8b0ab8d76f039b15e2bd8/41390948280.pdfIn PDF document text
    • http://giprozdraw.ru/ckfinder/userfiles/files/mupefoluwukasoka.pdfIn PDF document text
    • http://lasfyy.com/uploadfile/file/20210531164125060.pdfIn PDF document text
    • http://cuacongtudongbinhduong.com/upload/files/fizafakazuji.pdfIn PDF document text
    • https://underworldgear.com/upload/users/files/bupupamofuz.pdfIn PDF document text
    • https://www.rydalmereprestige.com.au/wp-content/plugins/super-forms/uploads/php/files/9825eqt0s88tlet10r6cqnv584/nikidawenawifupidobewan.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160bfb716d22c0---24986369559.pdfIn PDF document text
    • http://mobilenmr.com/files/files/vupomexagorafoder.pdfIn PDF document text
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082016b952a1---30101398244.pdfIn PDF document text
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160b451277dfdc---22498689405.pdfIn PDF document text
    • https://swiz.eu/files/editor/valatafigezinofibireme.pdfIn PDF document text
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606eab21ca0ab---59669458491.pdfIn PDF document text
    • http://jilienjrubin.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/14777186342.pdfIn PDF document text
    • https://www.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092eff2280e5---suriwimusenaw.pdfIn PDF document text
    • http://mingmitrcoffee.com/user_img/files/pataxoluzewekajeluze.pdfIn PDF document text
    • https://amrapalispot.com/userfiles/file/84376261147.pdfIn PDF document text
    • https://amd-export.com/site/upload/file/60750392326.pdfIn PDF document text
    • http://sibmetiz.ru/upload_picture/90850318418.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/199f46e426d30df57e7342bbb428ff18/ribejonov.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=free+summer+training+in+biotechnology+2020PDF 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_off0000c998.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC998 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e1af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1AF 11248 bytes
SHA-256: c8c116d77c571fd92389f2ba81994f1d55d558cc295689ef6ce69e2fbe2424a6
font_02_sfnt_off0000fbf3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBF3 17196 bytes
SHA-256: 57a7e53d0994bfb20ef23c2b82af0e8fbac075121c00aa2d4e7c945f8b200102