Malicious PDF — malware analysis report

Static analysis result for SHA-256 9851400a40f6c8cc…

MALICIOUS

PDF

81.6 KB Created: 2021-09-18 14:58:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: b86cc93a64e8cb3b18db461d6ae081ac SHA-1: a042e2723fd5fe6a4ec13042467855627b17f8a8 SHA-256: 9851400a40f6c8ccec1870ec6033e55c5a04dabd77ef8fbf9a7fe85b074b9d24
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories, indicating a link farm designed to redirect users to potentially malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the nature of the URLs and the heuristic firings point towards a phishing or credential harvesting attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://takiminsahada.com/wp-content/plugins/super-forms/uploads/php/files/01v0ek39rtegona73eaqe3bsi8/29943326541.pdf In PDF document text
    • https://granitabrasive.hu/editor_up/waxirewojunas.pdfIn PDF document text
    • https://langumeistras.lt/i/File/57265942177.pdfIn PDF document text
    • https://denimder.org/resimler/files/fivanos.pdfIn PDF document text
    • https://twinscooking.nl/twins/userfiles/file/kaxukejudanobozaw.pdfIn PDF document text
    • https://apz-arte.com/ckfinder/userfiles/files/toguretasawinifol.pdfIn PDF document text
    • http://impex-italia.it/userfiles/files/89291648802.pdfIn PDF document text
    • http://hugslock.com/app/webroot/img/files/guzixedewozonomunomazos.pdfIn PDF document text
    • https://118highschool.am/wp-content/plugins/super-forms/uploads/php/files/0340527c6273b5fee5e90260e56699f0/96672264621.pdfIn PDF document text
    • https://giltmorestukko.hu/ckfinder/userfiles/files/80086417852.pdfIn PDF document text
    • https://ecohort.info/userfiles/files/zixedejalesogofosobobov.pdfIn PDF document text
    • http://shriadinathbank.com/uploads/memumelojitoba.pdfIn PDF document text
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613711d6dd6f0---86436509782.pdfIn PDF document text
    • http://lawfirm.vn/MINH/user_files/file/39965819018.pdfIn PDF document text
    • http://shsuorui.com/uploadfiles/fckeditor/20210918/file/16319331624693.pdfIn PDF document text
    • http://standardamulet.com/files/files/gixuzo.pdfIn PDF document text
    • http://assessmentinsight.com/ckfinder/userfiles/files/vevoxamovobobuzev.pdfIn PDF document text
    • http://crescentcarpets.com/userfiles/file/35131053523.pdfIn PDF document text
    • http://sweed-trans.eu/ckfinder/userfiles/files/vufabatejoviraragod.pdfIn PDF document text
    • http://www.kroonzuivel.nl/ckfinder/userfiles/files/sowinulo.pdfIn PDF document text
    • http://michaelwilliamslaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/36817457690.pdfIn PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613ded298266a---54673550211.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=happymod+angry+birds+epicPDF 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_off0000d315.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD315 10956 bytes
SHA-256: c432f4a3b3aa316827000b25e2d08be2c098410746f976baaebf80d1130dc4d0
font_01_sfnt_off0000ebfe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBFE 19668 bytes
SHA-256: 7e09b424184cf6b0d460202e347b7d9e286b8b12ab4dbc87c3d739a3de3d0f2b
font_02_sfnt_off00011f79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F79 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1