Malicious PDF — malware analysis report

Static analysis result for SHA-256 f3cbafc71836a5de…

MALICIOUS

PDF

82.4 KB Created: 2021-09-11 08:02:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 6d1fdac946fca43f8a0186bff391ac63 SHA-1: cbd6bc1c41f063dac20b5a363e0b54f7d854963c SHA-256: f3cbafc71836a5de94ad740c854099502da08c985a576a55f12110fe65e34f2e
156 Risk Score

Malware Insights

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

The PDF contains a large number of links pointing to various domains, many of which are identified as compromised CMS uploads or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is unreadable, but the heuristic firings clearly describe the link farm behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://chugguwang.com/files/fckeditor/file/sibew.pdf In PDF document text
    • http://flexinform.com/hirlevel/file/weselisinalonumuxozav.pdfIn PDF document text
    • http://mitcostruttori.it/userfiles/files/3548928988.pdfIn PDF document text
    • http://fairfresh.net/assets/admin/ckeditorimage/files/neselaxujunimudip.pdfIn PDF document text
    • http://klick-tipp.at/ckfinder/userfiles/publics/files/zumubovafonaduwejixam.pdfIn PDF document text
    • http://ttmm.co.jp/ckfinder/userfiles/files/80134490121.pdfIn PDF document text
    • http://myblindz.com/fck_user_files/file/78066087616.pdfIn PDF document text
    • http://sochi-riba.ru/ckfinder/userfiles/files/bejunat.pdfIn PDF document text
    • https://nilsahost.com/calisma2/files/uploads/28392937459.pdfIn PDF document text
    • http://liweisteel.co.th/ckfinder/userfiles/files/93571316974.pdfIn PDF document text
    • http://opersan.com/file/wigewudotidigav.pdfIn PDF document text
    • http://lucchetta.net/userfiles/files/6769706282.pdfIn PDF document text
    • http://www.etoiles-recrutement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bcf89c45a4---36164876999.pdfIn PDF document text
    • http://safedoorsystems.com/cmsimages/file/12070095655.pdfIn PDF document text
    • http://www.fotografoeventimilano.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bca9ebbedf---68367308478.pdfIn PDF document text
    • http://frankslawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/tikepu.pdfIn PDF document text
    • http://dealershop.es/userfiles/file/getafaribonizudixig.pdfIn PDF document text
    • https://robert-zauer.cz/userfiles/file/78382036594.pdfIn PDF document text
    • https://gccpay.net/wp-content/plugins/super-forms/uploads/php/files/ebdf1b2e16fb26a0e07478de6b342a15/wurotikakirifa.pdfIn PDF document text
    • http://tongchangkj.com/uploadfile/file///2021090708544159.pdfIn PDF document text
    • https://ateneoarbonaida.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ab860ee6f6---zikezivotaxanujukux.pdfIn PDF document text
    • http://makinsushi.com/uploads/files/1167205209.pdfIn PDF document text
    • http://2safe4u.cz/UserFiles/File/levuvimo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=fortnite+unused+codesPDF 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_off0000da05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA05 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f21c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF21C 10232 bytes
SHA-256: d1e821be173d765cd5d6e5561514ee6cdbbacf4ea8541be217c845dfba327767
font_02_sfnt_off00010930.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10930 19404 bytes
SHA-256: 9ff4960c0be12ab09da60c0a16be1a42b4cb32c3be8caac7bee47e07d455aa30