Malicious PDF — malware analysis report

Static analysis result for SHA-256 6b52fd56c9da70f1…

MALICIOUS

PDF

87.4 KB Created: 2021-09-09 09:03:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 5416510055ea85988d90433878da7523 SHA-1: deb92a69e0c42459e3e3eec50d59b8e0f7b788ba SHA-256: 6b52fd56c9da70f10d204572b24b3bbb749f0db564e50d1033b0a17f23b75a63
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 compromised websites or disposable hosting, indicating a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, and the document body was unreadable, so the rationale is based on the URL analysis and heuristic firings.

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 https://laborke.ru/uplcv?utm_term=free+fire+cobra+game+download+for+pc PDF link annotation
    • http://dailycan.com/userfiles/files/lizusuvo.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/rt50lj6epdaqrgpngr1180img7/puzasivitav.pdfIn PDF document text
    • https://travellifeafrica.com/ci/userfiles/files/53420989494.pdfIn PDF document text
    • https://www.abrasco.org.br/ckfinder/userfiles/files/50156733625.pdfIn PDF document text
    • http://www.autoservis-hubatka.cz/admin/upload/ww/file/sesiti.pdfIn PDF document text
    • https://www.jdconstinc.com/ckfinder/userfiles/files/2920762045.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/8ojt77njbean7paib2e2otfr84/74735355954.pdfIn PDF document text
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16136d58092517---80618105311.pdfIn PDF document text
    • http://cgmorenanews.com.br/ckfinder/userfiles/files/jolawiguk.pdfIn PDF document text
    • http://tiendanatacion.com/noticias/files/64147761330.pdfIn PDF document text
    • http://rayer.cn/d/files/navekugujefuwizuwegoz.pdfIn PDF document text
    • http://lavalnerina.it/userfiles/file/judizovoturuxeralafu.pdfIn PDF document text
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/161324b5fad518---81500861691.pdfIn PDF document text
    • http://mmbc.cz/_data/user_files/file/34899715108.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/50ab4b754ff1ca1283a2891ddb50680d/17100823205.pdfIn PDF document text
    • http://cungcapbaoduongcuanhatban.com/upload/files/keroveloxowedosefinu.pdfIn PDF document text
    • https://kozlovka.mebel18.com/uploads/files/8706048244.pdfIn PDF document text
    • http://qianxish.com/ckfind_image/files/60396713356.pdfIn PDF document text
    • http://sowa-architekci.pl/userfiles/files/5221524156.pdfIn PDF document text
    • http://handgun.ee/media/file/ligezizavuxekar.pdfIn PDF document text
    • http://sunway.me/ROOT_PATHuploads/file/012122302216.pdfIn PDF document text
    • http://cleangroupbd.com/ck/upload/files/28900365422.pdfIn PDF document text
    • https://everestart.com/images/stories/file/wudole.pdfIn PDF document text
    • http://seamcc.com/UserFiles/files/46921781336.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_off0000eff9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFF9 18140 bytes
SHA-256: 3de2f97377fb95f992cafaf5c7b13d61cdd6474d913178742d8a4bed06632a35
font_01_sfnt_off00011f33.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F33 10900 bytes
SHA-256: eb453ac4f2f94a42c10bf04e0c4182fe2d4cdcd32ac00701f775bcc854113ee2
font_02_sfnt_off000137fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137FC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1