Malicious PDF — malware analysis report

Static analysis result for SHA-256 c353eb52a143e290…

MALICIOUS

PDF

74.3 KB Created: 2021-08-17 01:44:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: bebf8f475096da4e96e15259f8000e95 SHA-1: cd2d13964aebdb0e82504d05841fb2b3c00476e5 SHA-256: c353eb52a143e290720e096196c648c4aa0752b6c8294baab12bbf41a985bf32
156 Risk Score

Malware Insights

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

The PDF file contains numerous links, many of which point to compromised WordPress sites and disposable hosting, indicating a link farm designed for SEO manipulation or phishing. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution via these links. No scripts were extracted, but the structure and URL patterns are indicative of a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/f5108aa2d7d9c8adcc16e9b1100cfcfe/gaduvukexukevubutuluz.pdf In PDF document text
    • http://robotsuk.com/luckingbros.co.uk/userfiles/files/92843287244.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8c341b0003---34628338119.pdfIn PDF document text
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/optrtuamr1l54k26o279upm557/wubosiliwijezupezoximef.pdfIn PDF document text
    • http://baiduvpn.com/upload/files/kogukuj.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/vdh3v7gtfri37pvpdiosbml6bo/79054874339.pdfIn PDF document text
    • https://rfcorporation.net/wp-content/plugins/super-forms/uploads/php/files/31328bcc88fba1541dcb8781667d4399/gururakababamapavile.pdfIn PDF document text
    • http://954move.com/clients/4890/File/zufelapozufaxonuw.pdfIn PDF document text
    • http://anvlaw.com/userfiles/file/32732996681.pdfIn PDF document text
    • https://parisautotravel.com/wp-content/plugins/super-forms/uploads/php/files/otoilk7kk7eegjltj5gvnq4m01/kafobarigeku.pdfIn PDF document text
    • https://www.reachcast.ca/wp-content/plugins/super-forms/uploads/php/files/f444e243f6dff86fcedb3faaa62005b7/22899379880.pdfIn PDF document text
    • https://wegofa.com/userfiles/file/65883400863.pdfIn PDF document text
    • http://www.mtpartnersfl.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f537200858---2767283416.pdfIn PDF document text
    • http://czechnews.cz/userfiles/files/gomatewifuvigez.pdfIn PDF document text
    • http://duocthientam.com/uploads/ckfinder/files/zujegene.pdfIn PDF document text
    • http://kpdb.org/userfiles/files/72935751489.pdfIn PDF document text
    • https://sckstone.com/wp-content/plugins/super-forms/uploads/php/files/0ecbfae608242656adf90d1b3cf86bf1/34136867641.pdfIn PDF document text
    • http://score1forspencer.com/clients/4/45/4587145e2679cb7673d0e21b436e5c25/File/89449217357.pdfIn PDF document text
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/mokewovaresadixopu.pdfIn PDF document text
    • http://www.marcado.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607f709c0154e---5324195747.pdfIn PDF document text
    • https://actorconseil.com/files/file/90893702137.pdfIn PDF document text
    • http://tantusmarina.com/UserFiles/file/kijavudisewenoma.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=understanding+human+sexuality+7th+canadian+edition+pdf+freePDF link annotation
    • http://lovewhereyoulv.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/47a9af905126acd648caed0f9fc1e318/33296990984.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_off0000bedd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBEDD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d6ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6EF 16452 bytes
SHA-256: dcc51ab782ad2418d398da889a870d1ced4dc3f6ad9b5554fd383f005636170e
font_02_sfnt_off000100d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100D9 11440 bytes
SHA-256: d45d75dd75b2271a7577b59842b5d78890db60bad79c4804c2329d83013dbeef