Malicious PDF — malware analysis report

Static analysis result for SHA-256 55373674b6c9256b…

MALICIOUS

PDF

88.1 KB Created: 2021-08-17 00:19:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: a1112b90e337ee9c51675dc20a7bc010 SHA-1: 4a3011f580cf761c02c0528efad23bdaa23db2bc SHA-256: 55373674b6c9256b1b690ba5fca01d4c079a8b8135861fd6d3f383a97ed3a3d6
156 Risk Score

Malware Insights

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

The PDF contains a link farm directing to multiple URLs, many of which are hosted on compromised CMS platforms. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, and the document body was unreadable binary data.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://movesforfree.com/wp-content/plugins/super-forms/uploads/php/files/3ej56v51ifgrq1svr597v6f933/dagubepeje.pdf In PDF document text
    • https://firsatoyun.com/calisma2/files/uploads/faxixadimomu.pdfIn PDF document text
    • http://x-site.by/upload/editor/files/xedowivafu.pdfIn PDF document text
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160841bae6cd6c---2878965406.pdfIn PDF document text
    • http://horlickhigh61.com/clients/a/ab/ab3fb267cc30d45b98f460a20cee0b8d/File/8342578074.pdfIn PDF document text
    • http://pathtojanna.com/userfiles/files/370402858.pdfIn PDF document text
    • https://fjordancv.info/wp-content/plugins/super-forms/uploads/php/files/fa1d0a61deac2951107e066680148555/sibetiwed.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096a931d0929---rovoxanapumebovemowop.pdfIn PDF document text
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7386d1868c---vegokegolewuxi.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16083fcf55536d---jiruritijib.pdfIn PDF document text
    • http://ecovn.vn/uploads/news_file/82863560804.pdfIn PDF document text
    • http://www.afurg.com.br/assets/ckfinder/userfiles/files/subuxa.pdfIn PDF document text
    • http://pnmanagementsolutions.in/uploads/gadofopeba.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/c56m0pk543cfuvdprd6h97btl3/19866611801.pdfIn PDF document text
    • http://pwr-tech.ru/userfiles/file/zotafofudojefitule.pdfIn PDF document text
    • http://hongdacable.com/d/files/85501195804.pdfIn PDF document text
    • http://dafangtour.com/fckeditor/userimages/file/36228977617.pdfIn PDF document text
    • http://yummyschool.com/_UploadFile/Images/file/zalelixine.pdfIn PDF document text
    • http://muzeumostrowiec.pl/obrazy/file/razifutufusopanubumofu.pdfIn PDF document text
    • http://oralrem.kz/ckfinder/userfiles/files/webeteropemiv.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/5c87d36a501ccc0c9b2bab60b27fa532/majepewujuwojiwesidaxap.pdfIn PDF document text
    • http://sungsam.net/userData/board/file/77713714919.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/pvg7b6e5sihss3uiaf297cqip7/15994615906.pdfIn PDF document text
    • http://bobas24.pl/Upload/file/84431869050.pdfIn PDF document text
    • http://willettelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/13325018379.pdfIn PDF document text
    • https://www.corridar.com/wp-content/plugins/super-forms/uploads/php/files/kk7avscsiosl5m62udva5h5jah/fetibin.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=banana+blast+game+rulesPDF 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_off0000f776.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF776 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010f88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F88 16752 bytes
SHA-256: 00d12072c76cc32756b52623ca77dcb934c9b0d4c0b77e17804cfc8cca8efa8e
font_02_sfnt_off00013b14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B14 10532 bytes
SHA-256: aa4b866966957d273c6457c29c1c77eb8fab31039c4e24ed3536758b8884e094