Malicious PDF — malware analysis report

Static analysis result for SHA-256 25b9820c81a1e4d1…

MALICIOUS

PDF

83.1 KB Created: 2021-06-28 23:00:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 58d04c6eee0ddf775df0567f6a50a1ed SHA-1: eeaa9dbc3c506551d2a51c84e4918c16eea5a9e2 SHA-256: 25b9820c81a1e4d1f567ef01289ca7730d0b1723478ac45fc0b5af65c3f0b167
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to websites that appear to be compromised WordPress installations, as indicated by heuristics like 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM'. The ML classifier and ClamAV also flagged this PDF as malicious, specifically as a phishing trojan. While no scripts were directly extracted, the nature of the links suggests a phishing or malicious redirection scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9844

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 http://olddieselparts.com/ckfinder/userfiles/files/barojagaxareni.pdf In PDF document text
    • https://belgradenightlife.info/wp-content/plugins/super-forms/uploads/php/files/3obq6avmn723p3ehjitq4ljpvv/ginijebeminawemonifafem.pdfIn PDF document text
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4f28e60e8b---59041931704.pdfIn PDF document text
    • http://www.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a922589e851---40542485177.pdfIn PDF document text
    • http://spoanalyze.com/wp-content/plugins/super-forms/uploads/php/files/64c0beb6ed3880a852ece50ca6d5c07a/vasaxoredakonugajeze.pdfIn PDF document text
    • https://www.sevgiliyevideo.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a2c3c9511bd---31082256089.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/je4lstmrb6p2o1bndq7una1h71/52906495451.pdfIn PDF document text
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b041cc0ed21---dudumopolew.pdfIn PDF document text
    • http://kanstm.com/ckupload/files/fuguwadorede.pdfIn PDF document text
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a26fd230da9---pixazufarozoluwijat.pdfIn PDF document text
    • http://aptchasers.com/FCKeditor/userfiles/file/kubufedodutobiwekadekugej.pdfIn PDF document text
    • http://thingsantiquesla.com/userfiles/files/sadawoxatusesoneri.pdfIn PDF document text
    • http://msamericapageant.com/clients/873634/File/85700625449.pdfIn PDF document text
    • http://permianhighschool1970.com/clients/e/ef/efee9fcbc667252fc4b649c8163d3733/File/pasedulelapisol.pdfIn PDF document text
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b364176f8be---32996486497.pdfIn PDF document text
    • https://outsourcedbackoffice.co.uk/wp-content/plugins/super-forms/uploads/php/files/12040b160733109c5871a9a65995944f/wipotewubevidedikirepak.pdfIn PDF document text
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d630799a621---virotelixevixovojavewetub.pdfIn PDF document text
    • https://www.alignerco.ca/wp-content/plugins/super-forms/uploads/php/files/117d47804466a52a40d4de2ec77aa81a/fitiv.pdfIn PDF document text
    • https://www.cocochan.com.pk/wp-content/plugins/super-forms/uploads/php/files/b3b6867da580723ff0ec60ea103073f2/danilimudasatu.pdfIn PDF document text
    • http://2440027.ru/upload/file/45256093493.pdfIn PDF document text
    • https://sipsib.ru/wp-content/plugins/super-forms/uploads/php/files/2d42fe31088da7c8a17f1aab55aa5092/kexovip.pdfIn PDF document text
    • https://skyfireconsulting.com/wp-content/plugins/super-forms/uploads/php/files/7h5k9gh7cpdocbb5fjsvm7u70t/gelupunofurijukuvagodebi.pdfIn PDF document text
    • http://www.publicitymailing.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160927b903680f---teguzizafebetipa.pdfIn PDF document text
    • http://vienkiemis.lt/app/webroot/uploads/userfiles/files/17426399116.pdfIn PDF document text
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/160cb76b986c54---82939667813.pdfIn PDF document text
    • http://samuiluxurytravel.com/Uploads/file/dexiranozipubujedumadi.pdfIn PDF document text
    • https://www.nrlandscapes.co.uk/wp-content/plugins/super-forms/uploads/php/files/08e9fad72a64b152936ac106089c54a7/1000722454.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=kase+san+andPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cccb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCCB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e4dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4DD 24412 bytes
SHA-256: db8244c7f9184f1942707182f8d5bcd098f4108ce51110c04417f0575d4c333a
font_02_sfnt_off000119b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119B4 3432 bytes
SHA-256: f3b0990352af2c578018533310332cfb75cbc7ad61892e8629ab4b69ecb6e0a6
font_03_sfnt_off000127a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127A4 9776 bytes
SHA-256: 13b00a8d179dc8fa2a8b00cda6a5693464133c8a40e734ce9f4067458820cc84