Malicious PDF — malware analysis report

Static analysis result for SHA-256 c271af597ca475ba…

MALICIOUS

PDF

83.6 KB Created: 2021-09-20 14:30:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 14bcd6d5dd595eb9560b50bf9cf64183 SHA-1: 5a23b38513e41b38abb84022314dc45f180135a2 SHA-256: c271af597ca475ba8317b8e4bae0acc2557bde24786965aa2e21cf3eff3e434c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many hosted on 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 distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://doanhnghiepvietnam.niengiamdoanhnghiep.vn/img_duhoc/files/34147577331.pdf In PDF document text
    • https://www.premiumtrade.ro/ckfinder/userfiles/files/89959401560.pdfIn PDF document text
    • http://didula.ru/img/file/pejukirinaronoguso.pdfIn PDF document text
    • http://mariondhuique-mayer.com/data/file/40291848701.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/cf328a4ebaa63bbacab745f46eeb4ccc/redigiseju.pdfIn PDF document text
    • https://ms2gacor.com/contents/files/80525851483.pdfIn PDF document text
    • http://studiogallerani.it/userfiles/files/nokirikenikisajabilonof.pdfIn PDF document text
    • http://bangdinhphucat.com/quangbasanpham/app/webroot/upload/image/files/bijefonusol.pdfIn PDF document text
    • http://xn----8sbaqfskngn1qi.xn--p1ai/userfiles/file/38257668496.pdfIn PDF document text
    • http://taociren.com/upload/file/21091010023535162636pz57dgebyt.pdfIn PDF document text
    • https://braveathlete.net/geektic/files/39459859634.pdfIn PDF document text
    • https://lashmakerpro.it/wp-content/plugins/super-forms/uploads/php/files/rduegur1f5i9aghofuils35t17/xopejudivowavubojelok.pdfIn PDF document text
    • http://michael-dhom.com/webseiten/file/92648199591.pdfIn PDF document text
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613797c36e4fe---bifolubezetunudamo.pdfIn PDF document text
    • https://endeligmandag.no/e-brev/data/div/92131676455.pdfIn PDF document text
    • https://irisapp.cn/uploadfiles/fckeditor/20210914/file/16315627738440.pdfIn PDF document text
    • http://warungmimpishio.com/contents/files/melexe.pdfIn PDF document text
    • https://dukra.sk/editor_uploads/files/newul.pdfIn PDF document text
    • http://shuimotongyuan.com/userfiles/file/mebegewokodaropopemir.pdfIn PDF document text
    • https://kingwaterpure.com/ckfinder/userfiles/files/xonuluvakaremeg.pdfIn PDF document text
    • https://ottopianos.nl/files/domesenosutebap.pdfIn PDF document text
    • http://www.syrahresources.com.au/application/third_party/ckfinder/userfiles/files/11159641300.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=gifted+en+espa%C3%B1ol+peliculaPDF 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_off0000de65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE65 10856 bytes
SHA-256: 86d7e8487e2572c1ef7fef386e46919b9441396ef1d9a80307d7c4a4e055f49b
font_01_sfnt_off0000f75f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF75F 18500 bytes
SHA-256: f0fe964354dd6e5b357751696f4076d9e13847c8b3409b3c1a6c1048f3e7ec35
font_02_sfnt_off000126d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126D4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1