Malicious PDF — malware analysis report

Static analysis result for SHA-256 43f9f6b70867454f…

MALICIOUS

PDF

72.9 KB Created: 2021-09-14 12:05:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: c5d13a16ab5e0161a0603f3d707a0548 SHA-1: 8c26882de7a29556701e56e31126ff01a52f4041 SHA-256: 43f9f6b70867454f599ec0d5dd2b2e4ff5f2e16a239faa2b5fb658ad4af4d90b
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 uploads or disposable hosting, indicating a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were directly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://ecole.ru/text/images/file/gumoboxo.pdf In PDF document text
    • https://vinacomvietnam.vn/uploads/news_file/bevup.pdfIn PDF document text
    • https://anakaygame.net/calisma2/files/uploads/74054829473.pdfIn PDF document text
    • http://andreevmag.com/wp-content/plugins/super-forms/uploads/php/files/9edbdd5254c9552f2038552127fc2f03/96217097255.pdfIn PDF document text
    • http://importfoodfair.com/userfiles/image/2021/09/file/92317359630.pdfIn PDF document text
    • https://tainandentist.com/uploads/files/202109100127466550.pdfIn PDF document text
    • http://studioambienteterritorio.it/userfiles/files/43700563012.pdfIn PDF document text
    • http://tunesistudio.eu/userfiles/files/ruzanenosofep.pdfIn PDF document text
    • https://hidropomp2008.com/uploads/userfiles/file/jirifegus.pdfIn PDF document text
    • http://wronba.com/uploads/wysiwyg/file/gemisabeleki.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161387a9fe2bd8---kisusabu.pdfIn PDF document text
    • https://giraffeng.net/infodaily/gen-ckfinder/userfiles/files/zikekofupogomewa.pdfIn PDF document text
    • https://aradmissions.com/ci/userfiles/files/4596075730.pdfIn PDF document text
    • http://alicekhenrylawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/38432757090.pdfIn PDF document text
    • https://duel.pl/userfiles/file/zidugewezigexaleninov.pdfIn PDF document text
    • http://zekejozsef.eu/FCKfeltoltott/file/60111873374.pdfIn PDF document text
    • https://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/e64e5beacea00d5ed013d2b8a14e9e9f/83133507932.pdfIn PDF document text
    • http://moretonassets.net/userfiles/fatimobidukixa.pdfIn PDF document text
    • http://squarcialupirelaxinchianti.com/writable/public/userfiles/file/84905843606.pdfIn PDF document text
    • http://nwhouse.ru/uploads/file/46236161982.pdfIn PDF document text
    • http://www.yeosung21.or.kr/ckfinder/userfiles/files/1630865800.pdfIn PDF document text
    • http://pokrowce-ochronne.pl/Upload/file/5439254183.pdfIn PDF document text
    • https://best-of-geldanlagen.de/userfiles/file/wolupinoxipudusejozikipa.pdfIn PDF document text
    • http://superfasttv.com/uploads/files/31067730149.pdfIn PDF document text
    • http://xn----ctbguteehkho5h.xn--p1ai/ckfinder/userfiles/files/66303530358.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=metabolismo+del+nitrogeno+pdfPDF 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_off0000c04c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC04C 10976 bytes
SHA-256: 64317ab9eb9edc7b73ff0a9c76d1ec819924b5a9af20aac86e0c157f8dd78746
font_01_sfnt_off0000d947.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD947 14864 bytes
SHA-256: 1035ae8c1351c7b606974afcf35e07502f85326be5a69ddf18fb137a90286e57
font_02_sfnt_off0000fd88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD88 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1