Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb52b105dddde6bb…

MALICIOUS

PDF

75.5 KB Created: 2021-09-21 10:47:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 63e448bcd27e67d4ac65297b20da673e SHA-1: 34de1239b89e588a68ea5ab0c5ea2830e8ffb480 SHA-256: fb52b105dddde6bbbebd8a06317b8f7f2303fe10e2c0771e08237986029a2e45
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress uploads and disposable hosting, indicating a link farm designed to redirect users to malicious sites. ClamAV and ML classifiers confirm its malicious nature, likely as a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://asirius.su/wp-content/plugins/super-forms/uploads/php/files/8d75a95f655193bae61cee82b3292818/zixetadoxakubokenogidive.pdf In PDF document text
    • https://innovativallatgyogyszer.hu/fileok/file/jemegipegezuxibaw.pdfIn PDF document text
    • http://tc-muehlacker.de/data/tcmuehlacker/userfiles/file/kapawitusuzoziz.pdfIn PDF document text
    • http://agro-pasz.pl/ckfinder/userfiles/files/25331569681.pdfIn PDF document text
    • http://box8websites.com/ckfinder/userfiles/files/zinowe.pdfIn PDF document text
    • https://commonwealthsportsawards.com/userfiles/file/mofofinakowenisumuxigu.pdfIn PDF document text
    • https://geelaboba.dswip.com/ci/userfiles/files/86545568644.pdfIn PDF document text
    • http://k12kos.com/ckfinder/userfiles/files/dekitesozalogefupezepaz.pdfIn PDF document text
    • http://kco.su/userfiles/file/17927302883.pdfIn PDF document text
    • http://delfosventures.eu/userfiles/files/94182378504.pdfIn PDF document text
    • http://www.psychophonie-tarbes.com/ckfinder/userfiles/files/1859226863.pdfIn PDF document text
    • https://verredistri.fr/xmedia/file/fowagipuzawilozu.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614546d4af8cf---jidudejamow.pdfIn PDF document text
    • https://markyatirim.com/resimler/files/26039816020.pdfIn PDF document text
    • https://dcicz.org/userfiles/file/rofexodakemowadok.pdfIn PDF document text
    • http://ptk-astana.kz/wp-content/plugins/super-forms/uploads/php/files/8f60c6313408f8a8a9ba1249de295f16/fogodatitelabisu.pdfIn PDF document text
    • http://mya1fc.com/files/ckuploads/files/bupakarajakovarosufaruv.pdfIn PDF document text
    • http://anindecor.pl/files/file/tujedunukubekezolukere.pdfIn PDF document text
    • http://expnavi.com/sites/all/sites/default/files/file/35707530826.pdfIn PDF document text
    • http://casaledellasignora.it/userfiles/files/25019159576.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=domain+and+range+of+circular+functionsPDF 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_off0000bc92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC92 19504 bytes
SHA-256: 4c4cf826b239ecf75590c4aa9fb3676ed868d04d073da7f7eb6223c22e668799
font_01_sfnt_off0000ef7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF7C 10920 bytes
SHA-256: 53b96c3391aab8ace5bffc846144f2cad75de8725f9bb0042571771d10e5293c
font_02_sfnt_off0001088c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1088C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1