Malicious PDF — malware analysis report

Static analysis result for SHA-256 16f1095d83ce6f66…

MALICIOUS

PDF

80.7 KB Created: 2021-09-18 21:34:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: e4ecb86826ad96e492ecd5593be5a7bf SHA-1: a88b7540c7430967ef5a89d030350ad93c0b6b00 SHA-256: 16f1095d83ce6f665c2341842ea9540242cf481ef1791949c54bb2b50a40d8ac
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

The PDF contains a large number of external links, many pointing to potentially compromised or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery through these links. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the link structure and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://0975811252cool.linker.tw/files/70026724609.pdf In PDF document text
    • https://marblobathware.ph/app/webroot/img/files/86185255507.pdfIn PDF document text
    • http://tatugigo.com/ckfinder/userfiles/files/tozazavavarawa.pdfIn PDF document text
    • https://realxenon.ru/uploads/files/ganavetovomarewo.pdfIn PDF document text
    • http://yingtailong.com/upload/file/210905143136421016gn6kzsikv8jg.pdfIn PDF document text
    • https://euroroma-bg.org/files/file/fotog.pdfIn PDF document text
    • https://hanoihome.net/img_duhoc/files/99627004864.pdfIn PDF document text
    • https://autoprofi.ua/userfiles/file/33191556053.pdfIn PDF document text
    • http://ahnil.com/userData/board/file/zajonepatosatabuxamep.pdfIn PDF document text
    • http://hasicimosnov.cz/foto/Image/file/93433014556.pdfIn PDF document text
    • http://lexxyin.net/files/fckeditor/file/35729558458.pdfIn PDF document text
    • http://selidbe-beograd.info/files/faratumegu.pdfIn PDF document text
    • http://rockhousemethod.com/ckfinder/userfiles/files/57557495265.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612eaa803978d---70861634719.pdfIn PDF document text
    • https://cplastik.net/data/cms/file/20813015308.pdfIn PDF document text
    • http://gocoachfox.com/userfiles/file/badagepedevujevewun.pdfIn PDF document text
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ad1d48bfc1---80229713843.pdfIn PDF document text
    • http://businessplan-capalpha.eu/mbp/upload/images/images/upload/ckfinder/faribeg.pdfIn PDF document text
    • http://baheth24aqari.com/ckfinder/userfiles/files/wabamagijaxikijoluxogado.pdfIn PDF document text
    • http://www.bestlifepolicy.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613c2d2337155---xawilagapigijenojetu.pdfIn PDF document text
    • http://pincailight.com/zk/UploadFile/file/2021090401014473499.pdfIn PDF document text
    • http://hatdesechia.com/storage/ckfinder/files/guranififixujigorixe.pdfIn PDF document text
    • https://mariapolis.net/ckfinder/userfiles/files/13541869590.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/69f35dccedae9096c205348c14eee09d/lemidolozikenad.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=tenet+torrent+downloadPDF 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_off0000d1e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1E6 19828 bytes
SHA-256: eb7965c8eee4ce67263312b27f382f46808198bb8f1af0364a3830f8318b8437
font_01_sfnt_off00010507.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10507 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011d1e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D1E 10032 bytes
SHA-256: 9fb088787feeedd61499aea8c47cb21f0f324b3320d58b8f523e2ade527baaec