Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd91f738929535b4…

MALICIOUS

PDF

61.2 KB Created: 2021-10-01 03:47:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: ff117241eae35f7aca1a28cde65dcb83 SHA-1: 6dc9f53fdc74006b840a69bd775dfe856fbd4070 SHA-256: cd91f738929535b4266b964c039f3e86db0bf789b6b7726107cb8ec804eaef57
132 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample contains embedded JavaScript, a common technique for executing malicious code within PDFs. Heuristics indicate the PDF acts as a link farm, directing users to compromised WordPress sites and disposable hosting, likely for phishing or malware distribution. ClamAV detection confirms its malicious nature, identifying it as Pdf.Phishing.Trojan.

Machine Learning

  • Nyx PDF Classifier suspicious score 0.4064

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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://thingstodobahrain.net/ckfinder/userfiles/files/22877477989.pdf In PDF document text
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/806d9d5bb4e4c3de811c4e6dd7840309/52968535317.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/16142e9f473360---nakujulefowidak.pdfIn PDF document text
    • https://vico-real-estate.com/ckfinder/userfiles/files/jevot.pdfIn PDF document text
    • http://studiobonvino.com/userfiles/files/kufug.pdfIn PDF document text
    • http://appartenvue.net/appart/upload/images/xigakomufinesaxenox.pdfIn PDF document text
    • https://bodymart.in/ckfinder/userfiles/files/legad.pdfIn PDF document text
    • https://alpinashop.rudy-ra.com/files/gitubifixibitogigevose.pdfIn PDF document text
    • http://euredit-editions.com/userfiles/file/mexumutagidugivoribigutol.pdfIn PDF document text
    • http://xn--e42bt3l.net/upfile/files/49799993636.pdfIn PDF document text
    • http://www.leads-bd.org/app/webroot/js/ckfinder/userfiles/files/nofeluronipuzewukokizew.pdfIn PDF document text
    • http://ichieh.tw/uploads/files/202109161206265779.pdfIn PDF document text
    • http://life-homeshop.com/asset/uploads/files/kixevuzobaruminetudi.pdfIn PDF document text
    • http://builderall.info/userfiles/file/5828295303.pdfIn PDF document text
    • https://rimsball.com/ckfinder/userfiles/files/debod.pdfIn PDF document text
    • https://www.fyna.com.au/application/third_party/ckfinder/userfiles/files/14573018193.pdfIn PDF document text
    • http://kidzcastleschool.com/singhania/downloads/file/72022772036.pdfIn PDF document text
    • https://rosedreamholidayhomes.com/ckfinder/userfiles/files/34421043799.pdfIn PDF document text
    • http://startmatbaa.com/userfiles/file/tojudojixefiz.pdfIn PDF document text
    • https://tigaintan.com/contents/files/75793223621.pdfIn PDF document text
    • http://csc0731.com/userfiles/file/20210929184811_urnexg.pdfIn PDF document text
    • http://czpohledavky.cz/userfiles/files/3380724123.pdfIn PDF document text
    • http://www.enredmail.com/templates/files/idCliente_/file/rufalejisidivudaretotus.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16155d396eed99---zesobemomom.pdfIn PDF document text
    • http://www.catalogodecineargentino.com/wp-content/plugins/formcraft/file-upload/server/content/files/161506bf3ca749---44671300813.pdfIn PDF document text
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/16141916eceb30---fixapo.pdfIn PDF document text
    • http://4els.ru/uploads/images/files/89669175490.pdfIn PDF document text
    • http://tw-sincere.com/upfiles/editor/files/siwonaxifesofonun.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=myket+android+storePDF link annotation
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b384.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB384 15188 bytes
SHA-256: 9971b94890827fb604ec06fda927005feb885ce381d296567e416681901a9894
font_01_sfnt_off0000d97c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD97C 10396 bytes
SHA-256: 12551bb1fd032a81a9ff9dd666d5ca01c7e66494c88a49bd238a785353645eae