Malicious PDF — malware analysis report

Static analysis result for SHA-256 51bec926e52f0349…

MALICIOUS

PDF

87.5 KB Created: 2021-09-14 11:37:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: e3c23a5405576509a5eccfc0e326052c SHA-1: d1d8b3475ce434f3e79be908e52179f4b3abcb57 SHA-256: 51bec926e52f0349f093e2ddb5f23df20eebdfb80ca4c825f7832c4e4a409537
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to various domains, many of which are hosted on compromised CMS upload storage or disposable hosting, indicating a link farm designed to obscure malicious destinations. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for 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 sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://www.bluewhaleline.com/image/upload/File/93248604552.pdf In PDF document text
    • https://stcc-sa.com/motakamel/Ups/files/somigalibitamiwilene.pdfIn PDF document text
    • http://dxline.eu/userfiles/file/7968402475.pdfIn PDF document text
    • https://leunamgroup.com/wp-content/plugins/super-forms/uploads/php/files/0552afa7a0f1032831a0508c347f632c/vifodulobavijujasegofuse.pdfIn PDF document text
    • http://doubles301.jp/files/ckeditor/files/98448161456.pdfIn PDF document text
    • http://italiangreyhound.pl/img1/userfiles/file/nuxixexupow.pdfIn PDF document text
    • http://parkety-patemal.sk/files/file/62316727563.pdfIn PDF document text
    • https://www.eecpowerindia.com/codelibrary/ckeditor/ckfinder/userfiles/files/jevejitemenawudav.pdfIn PDF document text
    • http://residenceraffaellotorino.com/userfiles/files/jukibalogapudepi.pdfIn PDF document text
    • https://china-glass-mosaic.com/userfiles/files/20210831_184948.pdfIn PDF document text
    • http://www.tecnotrefg.it/wp-content/plugins/formcraft/file-upload/server/content/files/16133016da7990---40556866493.pdfIn PDF document text
    • https://yk-tech.com.tw/ckfinder/uploads/ckfiles/files/91526894888.pdfIn PDF document text
    • https://floraplant.gr/FCKeditor/userimages/file/18697469415.pdfIn PDF document text
    • http://studioaba.net/userfiles/files/1235302507.pdfIn PDF document text
    • http://xnucleus.com/members/member_images/files/tavazu.pdfIn PDF document text
    • https://demircanticaret.com/userfiles/file/12546207183.pdfIn PDF document text
    • http://rootbeadmill.com/upload_fck/file/2021-9-3/20210903113015341819.pdfIn PDF document text
    • https://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134c58a13135---63009320641.pdfIn PDF document text
    • http://media-production.net/admin/ckfinder/userfiles/files/notafamizugeritobiwevig.pdfIn PDF document text
    • http://le-bouquet.be/userfiles/files/16655191320.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=watch+you+me+her+season+3+online+freePDF 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_off0000f1ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1BA 10980 bytes
SHA-256: e6eb7fcfe606b700abc8c825434e5cf4fd280b87b343ed438a2e3cdd22b8bb0e
font_01_sfnt_off00010b1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B1F 17660 bytes
SHA-256: 469afe85b4f78b9d41bce9ccbf28e92a7b355db5ab995fa39f49b80f47aea775
font_02_sfnt_off00013926.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13926 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1