Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb16c8ecffcad546…

MALICIOUS

PDF

83.1 KB Created: 2021-09-11 23:12:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 1bf6258c1ce948f20e529920ac311428 SHA-1: 2657fe15a0763dd2aace181da95afbcb0d9ba8e7 SHA-256: cb16c8ecffcad5464b1a5d9251e738ea8c3dc15fbee7550724c74086356c85b3
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to disposable domains, indicating a link farm designed for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards a phishing attack, likely using embedded JavaScript to facilitate redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://podgoricki-klub.me/userfiles/file/fofokuforomida.pdf In PDF document text
    • http://agnieszkapawlik.com/userfiles/file/44659487094.pdfIn PDF document text
    • https://cmflower-kkc.com/ckfinder/userfiles/files/lidubilevuj.pdfIn PDF document text
    • http://aotem.com/data/home/qxu1780220113/htdocs/uploadfile/files/65301603702.pdfIn PDF document text
    • http://kinel-hunter.ru/upfiles/file/84757802379.pdfIn PDF document text
    • http://80tner.netsociality.com/upload/files/wemusuwut.pdfIn PDF document text
    • http://www.1atlanticfunding.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130fd3a91bf6---7176120075.pdfIn PDF document text
    • https://minhvuongthuphap.com/upload/ck/files/14211461003.pdfIn PDF document text
    • http://3qbuy.com/CKEdit/upload/files/69467042880.pdfIn PDF document text
    • http://tndgdemo2.com/ckfinder/userfiles/files/badofitidigetifedutulaxor.pdfIn PDF document text
    • https://takiminsahada.com/wp-content/plugins/super-forms/uploads/php/files/g4gff2ndijru59ko83qbmtc49p/55973510367.pdfIn PDF document text
    • http://yokohama-model.com/userfiles/files/16388504623.pdfIn PDF document text
    • https://washlounge.in/ckfinder/userfiles/files/56532953588.pdfIn PDF document text
    • http://dayou.tw/uploadpic/files/202109101047487835.pdfIn PDF document text
    • http://ourconn.com/userfiles/file/202109021552199746.pdfIn PDF document text
    • http://dfwarbitrator.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/11498188259.pdfIn PDF document text
    • https://wangwangcamp.com/uploads/files/202109111547428410.pdfIn PDF document text
    • http://kbautotech.com/board/datafiles/imagefile/tazofoxowafowulire.pdfIn PDF document text
    • http://fred-robin.com/ckfinder/userfiles/files/14446403813.pdfIn PDF document text
    • https://aalatour.com/basefile/b2caalatourcom/files/69047863163.pdfIn PDF document text
    • http://marketypik.pl/zdjecia/fck/file/71399090056.pdfIn PDF document text
    • http://daehnfeldt.com/userfiles/file/fobugax.pdfIn PDF document text
    • http://ottotech.center/userfiles/file/luwiviropulevukirudan.pdfIn PDF document text
    • https://mmagame.com/userfiles/file/gemorez.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=green+screen+tiktok+androidPDF link annotation
    • http://alessandrotria.altervista.org/areap/ckfinder/userfiles/files/50469005717.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_off0000dec1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEC1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f6d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6D3 18656 bytes
SHA-256: 34f203ce5a5552c58916e0839e9f5427f43fa3331a41e69e8f6709b458450ab7
font_02_sfnt_off000126c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126C5 10448 bytes
SHA-256: 28b3047fed96a0090fb6b89b08d2b86d73a4309a6d2d13171c9d6c9dcf24056c