Malicious PDF — malware analysis report

Static analysis result for SHA-256 5c66467b80c4edc9…

MALICIOUS

PDF

79.5 KB Created: 2021-07-03 12:18:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: a55dfbd4f47fefe965ca9fb927c29170 SHA-1: 0c7d937a5ae20e801c9400a113e071fdfe552c82 SHA-256: 5c66467b80c4edc90b1f16c9a051cf67dc73e135f60d6f10e04f8c7e03642d89
156 Risk Score

Malware Insights

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

The PDF document contains a large number of links pointing to compromised WordPress sites and other domains, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the embedded URLs are the primary indicators of compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://krisoc.ru/uplcv?utm_term=relativity+special+general+and+cosmological+pdf PDF link annotation
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/ea55962a4aad0d1d1a0ba78519879878/12722011594.pdfIn PDF document text
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607730bf6fb76---10702975541.pdfIn PDF document text
    • https://rockoncharters.net/home/rock/public_html/ckfinder/userfiles/files/55677546023.pdfIn PDF document text
    • https://gulfsupremesa.com/ckfinder/userfiles/files/fatomobafuramanubitusi.pdfIn PDF document text
    • http://alsumiri.net/wp-content/plugins/super-forms/uploads/php/files/15fe5c7383949c59f13db455d2be0fdf/29483511586.pdfIn PDF document text
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f59fbdf906---polijinudonerav.pdfIn PDF document text
    • http://adabaskimerkezi.com/upload/file/73699534481.pdfIn PDF document text
    • http://tykhestudiodesigns.com/clients/7/73/7311521ca682816632878891c231d107/File/gokopavopipesuzuvisaxof.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/tgn1ukmot7rp096t2ud9ucnfm2/ladivolugorojifawajarowuz.pdfIn PDF document text
    • http://rufullthrottle.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607938674fb5c---22359003556.pdfIn PDF document text
    • http://maslatalaia.com/userfiles/file/dojafafajimorizowewexivas.pdfIn PDF document text
    • http://wo-kop.pl/userfiles/file/pezoxozulimen.pdfIn PDF document text
    • https://graffitipaintstudio.com/wp-content/plugins/super-forms/uploads/php/files/53d6b92fba81ec4ae8f5fff1df52e1f7/kividisofol.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/160b579996873f---tixekukupuzisutaxe.pdfIn PDF document text
    • https://htlexpress.com/ckfinder/userfiles/files/49813434712.pdfIn PDF document text
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/0b3d061985ac1df01d4774cd02fa5e5e/lagawakofefav.pdfIn PDF document text
    • http://lorofilmes.com/Uploads/ckfinder/userfiles/files/puxokuvizal.pdfIn PDF document text
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/160b574e24df3a---monanuzinas.pdfIn PDF document text
    • http://alibabashipping.com/userfiles/file/7027040930.pdfIn PDF document text
    • http://tktravel.shop/FileData/ckfinder/files/20210615_66E315378518557A.pdfIn PDF document text
    • https://kisikana.hr/userfiles/file/15734303452.pdfIn PDF document text
    • https://tkpmission.org/wp-content/plugins/formcraft/file-upload/server/content/files/16097b044d479c---wixuxanofejobobu.pdfIn PDF document text
    • http://aclamerica.com/customers/CMS-IMAGES/file/73396530300.pdfIn PDF document text
    • https://zahnersatz.pl/userfiles/files/55076553684.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_off0000d15e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD15E 16672 bytes
SHA-256: 9c8151c12215ae84d02a48e9afe4d9779a213e1764663515427cbb142b4be42f
font_01_sfnt_off0000fca4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCA4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000114bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114BB 11188 bytes
SHA-256: b3fee46ea9d176aea295abb0086003aca08a866da4c22565fee7d33bc0aaf011