Malicious PDF — malware analysis report

Static analysis result for SHA-256 c16c619ae1041bd2…

MALICIOUS

PDF

73.7 KB Created: 2021-09-25 02:58:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: eb625c09b64c0f10b64ebfde05de6cdf SHA-1: e9161bb7d789e9ae20adfc4ecce642afb32638e6 SHA-256: c16c619ae1041bd226372c0b92efa87ef8f2692fc77c080f4c3908b5b24f1015
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristic firings reveal it functions as a link farm, directing users to numerous external URLs, many of which are hosted on disposable domains. The presence of embedded URLs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic strongly suggest a phishing or malware distribution campaign, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://wastran.ru/uplcv?utm_term=wifi+direct+firestick PDF link annotation
    • http://sino-web.net/filespath/files/20210902153258.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/c78r5em0q4l0pr0e378subo7jj/xopubepuvebuxoxowawalu.pdfIn PDF document text
    • http://cadeco.com/testingsites/advantage_aviation/assets/media/file/11966247584.pdfIn PDF document text
    • http://bassbasement.org/userfiles/file/rebotopivosoxesix.pdfIn PDF document text
    • https://bakotech.at/uploads/ckeditor/files/fuxebuxinujimi.pdfIn PDF document text
    • http://huyminhplastic.com/upload/files/jemetewodizibigem.pdfIn PDF document text
    • http://jfac.kr/ckfinder/userfiles/files/wejivaxejenebinaza.pdfIn PDF document text
    • http://websteravelandscaping.com/editorData/file/43099802896.pdfIn PDF document text
    • http://www.amedna.com/userfiles/files/95735193579.pdfIn PDF document text
    • http://propack-th.com/image/upload/File/wumanilifibebuxewiwaxuw.pdfIn PDF document text
    • http://xn--80aafbkbafwdti1ahihccrg.xn--p1ai/pict/file/20345902028.pdfIn PDF document text
    • https://rent-1.es/ckfinder/userfiles/files/tevomo.pdfIn PDF document text
    • http://agriturismoilnoceto.com/userfiles/files/67250817762.pdfIn PDF document text
    • http://kingalbertltd.com/uploadedfiles/file/vikizoz.pdfIn PDF document text
    • http://www.temaricerca.com/entry2013/admin/ckfinder/userfiles/files/wefazifopofetoladomitujo.pdfIn PDF document text
    • https://mpressivelabels.com.au/application/third_party/ckfinder/userfiles/files/39261800893.pdfIn PDF document text
    • https://vientangluc.com/upload/files/rewixuganituluwojodepi.pdfIn PDF document text
    • http://bigbazar.cz/is/images/FCKeditor/File/nijajasijodug.pdfIn PDF document text
    • http://smartdeal.pl/files/upload/files/58682442565.pdfIn PDF document text
    • http://thuonghieutoancau.vn/uploads/files/55016018790.pdfIn PDF document text
    • http://innotack.com/userfiles/file/gusokituwarowemusab.pdfIn PDF document text
    • https://www.sahabatkeluargahomecare.com/wp-content/plugins/formcraft/file-upload/server/content/files/161422f0589e73---nonasuvujojoz.pdfIn PDF document text
    • https://hse.tw/upload/file/jamovoranavidaseba.pdfIn PDF document text
    • http://erex.hu/upload/file/96671662468.pdfIn PDF document text
    • http://dgkno.cn/upload/51115452853.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_off0000b885.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB885 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d097.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD097 19144 bytes
SHA-256: 715b2fa8b3af3a34004f16f316ae240544ece015cb10e856f0feaf856986c648
font_02_sfnt_off0001028f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1028F 10124 bytes
SHA-256: e460ebe9440a2151dd7e9dcdf2290c7f40a63953b3a2ace4439f67dfd188bf17