Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9436e3b22d36a8c…

MALICIOUS

PDF

72.0 KB Created: 2021-09-18 00:50:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 394b3fd9676229bf64373e65e903c37f SHA-1: 825e86365835409d826c5b8efed3237e9e74809a SHA-256: a9436e3b22d36a8cd8e3b779b22724ba846a938efec51a94b423b50e43088fd7
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to other PDF files hosted on various domains. Several heuristics indicate this is a link farm, with some links pointing to compromised CMS upload storage. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO spam.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://indcms.testingmachines.com/images/file/fizitanuwesonofo.pdf In PDF document text
    • http://pathtojanna.com/userfiles/files/13885535794.pdfIn PDF document text
    • https://textosl.com/upload/editor/file/245255687.pdfIn PDF document text
    • https://coverline.ro/userfiles/file/wowepiwopokatixivu.pdfIn PDF document text
    • http://condosworld.com/abisol1/userfiles/files/7766388563.pdfIn PDF document text
    • http://xn--krmer-dnnebacke-1kb72b.de/files/file/4685589341.pdfIn PDF document text
    • https://terracell.pt/images/file/savaravo.pdfIn PDF document text
    • https://deesudcoolingtower.com/userfiles/file/79242265940.pdfIn PDF document text
    • http://casms.org/atts/news-files/file/wafemuj.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614508271421c---50698959925.pdfIn PDF document text
    • http://shtaket46.ru/page_edit/_samples/userfiles/files/65079778509.pdfIn PDF document text
    • https://fortlauderdale-carservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ea2ac459b7---mowirolipevap.pdfIn PDF document text
    • https://weblative.com/wp-content/plugins/super-forms/uploads/php/files/jd9v72r3ejaoue4ivbm4hi9e6j/piluwajuxox.pdfIn PDF document text
    • http://www.maderas-navarro.com/ckfinder/userfiles/files/daputizidej.pdfIn PDF document text
    • https://estudiowebcolombia.com/ckfinder/userfiles/files/tawenadobivemasewejuvus.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614214b23e4ed---juzetefibonal.pdfIn PDF document text
    • http://kibbkw.com/uploads/files/71865704684.pdfIn PDF document text
    • http://iucecb.com/files/file/30611855542.pdfIn PDF document text
    • https://intrastorg.com/userfiles/file/56374322197.pdfIn PDF document text
    • https://stealthwindow.tw/uploads/files/202109140527561524.pdfIn PDF document text
    • http://porpora.biz/imagenes/imagenes_contenidos///fatopimusimome.pdfIn PDF document text
    • http://georgekoldun.com/var/upload/file/25922755178.pdfIn PDF document text
    • https://home18.ru/wp-content/plugins/super-forms/uploads/php/files/44f9490abc975a36cbb8173b71c53100/92525491692.pdfIn PDF document text
    • https://casasholidays.com/scgtest/team-explore/uploads/files/37257397565.pdfIn PDF document text
    • https://emons-verlag.com/testarea/cwsCMSlight/media/files/fujevupuwavig.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=fifty+shades+darker+film+fullPDF 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_off0000b6a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB6A3 10676 bytes
SHA-256: b2ed7f20100a48bb5fbaa766878c6ccc5871c91521fd117e4001ff8f9d242b00
font_01_sfnt_off0000cf1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF1C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e72e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE72E 16796 bytes
SHA-256: 9a2715d74453acc73c6000943ae657717c696d177d853b0b5b8b7448507eb5b8