Malicious PDF — malware analysis report

Static analysis result for SHA-256 bb91c7ed776f468b…

MALICIOUS

PDF

83.3 KB Created: 2021-09-06 03:44:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: a4cc70c9a66b99490e006a9e1616a775 SHA-1: ad7f42957adab52141d57d9c8ec7ab25af17d5c8 SHA-256: bb91c7ed776f468b9db1047519cc6658985a1067427309353fb485b8ca30b121
156 Risk Score

Malware Insights

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

The ML classifier and ClamAV detection strongly indicate maliciousness. The PDF contains numerous links to external websites, many hosted on compromised CMS uploads, suggesting a link farm designed to redirect users to potentially malicious content or phishing sites. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://bmsorganica.com/userfiles/file/2918984651.pdf In PDF document text
    • https://cbolean.com/wp-content/plugins/super-forms/uploads/php/files/b4jpp58cv53n0fc1hjld0jna81/59766699387.pdfIn PDF document text
    • https://leesman.com/wp-content/plugins/super-forms/uploads/php/files/55be329890bd0d0fe0e115770d40cc40/zejoniva.pdfIn PDF document text
    • https://www.hontoys.com.au/wp-content/plugins/super-forms/uploads/php/files/ar4ro8esgbueqed9b789lori2i/refun.pdfIn PDF document text
    • https://www.dekleinewerf.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16108e6d4a522f---tusuwax.pdfIn PDF document text
    • https://synersys.fr/contenu/file/27421809987.pdfIn PDF document text
    • http://paroissedementon.fr/upload/files/guguwixurox.pdfIn PDF document text
    • http://myucpb.net/userfiles/file/lezegikojime.pdfIn PDF document text
    • http://wilkinsconnection.com/clients/9/94/94ba1e7d864c5c8af3bb481f5f9f31de/File/89730798843.pdfIn PDF document text
    • http://rotarycochinharbour.org/ci/userfiles/files/13900780317.pdfIn PDF document text
    • https://doanhnghiepvietnam.org/img_duhoc/files/9490576398.pdfIn PDF document text
    • http://thuocnam.xyz/images/files/wepozebazebozipire.pdfIn PDF document text
    • http://maslatalaia.com/userfiles/file/75434828527.pdfIn PDF document text
    • https://encoregallery.us/wp-content/plugins/super-forms/uploads/php/files/8f482985cffe686b8c12c199d286af08/66197330865.pdfIn PDF document text
    • http://www.dj-csnl.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c9b1ce12e4e---pikitosa.pdfIn PDF document text
    • http://parzenica-bialka.pl/userfiles/files/lufaburole.pdfIn PDF document text
    • https://guruamardaspublicschool.com/userfiles/files/58521118037.pdfIn PDF document text
    • http://szerecsen.hu/editor_up/61678502318.pdfIn PDF document text
    • http://yngc.ru/admin/ckfinder/userfiles/files/bulawuxafisigipo.pdfIn PDF document text
    • https://xn--i1aam8cb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/5787dabcd93ab05ea87dd77abf55e28d/befoxewebuko.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=civics+and+economics+review+worksheetsPDF 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_off0000de4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE4F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f666.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF666 10864 bytes
SHA-256: fdbb963ea6e536ab7717076c88640cb5890bca34b557b69eb8c3c94383f5869c
font_02_sfnt_off00010f6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F6B 18556 bytes
SHA-256: d03decefe3f5f6e34f635911d69469c1372f777a02a71e644dbf343348bc87c0