Malicious PDF — malware analysis report

Static analysis result for SHA-256 21763cbb9e2147b6…

MALICIOUS

PDF

83.9 KB Created: 2021-06-21 09:12:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-14
MD5: c5e2b83d7140b714aca06628bb5447d0 SHA-1: f5055d59dc629fc03bfcdf725e8d36079d0b3e85 SHA-256: 21763cbb9e2147b695f4520b109832ce6a9ad726be198d29e4a32e2878a9a9e1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains numerous links to external websites, many of which are hosted on compromised CMS uploads or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were directly extracted, the PDF structure and embedded URLs point towards an attempt to lead users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://allasclub.com/campannas/file/74655233256.pdf In PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/8c79cb9j0alh1iv6auv2ukdpl2/wumejepidilalaj.pdfIn PDF document text
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606f65adb1490---92908198113.pdfIn PDF document text
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/160824c1d0b35e---kefejotonulilu.pdfIn PDF document text
    • http://www.danvillern.com/wp-content/plugins/super-forms/uploads/php/files/dqv0cq2ec5hntcigjh31o7avg6/vawotamemufoburevitatawi.pdfIn PDF document text
    • https://backcountryplayground.com/wp-content/plugins/super-forms/uploads/php/files/143a27482e9c0f678d2c9b6c87812fe6/nerezol.pdfIn PDF document text
    • http://www.lightingandhvacexpo.com/wp-content/plugins/super-forms/uploads/php/files/f2c4be65d9e1948aba18c8ba8173342c/fedadovisisijekivigiguzef.pdfIn PDF document text
    • https://premium-house.uz/images/file/dedokufuzigebunese.pdfIn PDF document text
    • http://modamoda.nl/uploads/pic_lib/file/bewalejorode.pdfIn PDF document text
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607330510a0f4---lobogubonofe.pdfIn PDF document text
    • https://dodomacnosti.net/data/file/lirapi.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/160b32d3683709---gibikudanuda.pdfIn PDF document text
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a001f912331---xiribojifuj.pdfIn PDF document text
    • https://www.sehersirin.com/wp-content/plugins/formcraft/file-upload/server/content/files/160727311214b5---nabowu.pdfIn PDF document text
    • https://www.mybizwebsites.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608757cd43e91---97501622375.pdfIn PDF document text
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/59a10af71de7914a06075cfd1d312955/60494921795.pdfIn PDF document text
    • https://petala.gr/userfiles/file/71328569839.pdfIn PDF document text
    • http://aelma.com/sites/default/userfiles/file/fojosegafejoj.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=guided+meditation+to+ask+spirit+guides+for+helpPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010cfa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CFA 5548 bytes
SHA-256: c09e966134086c16c9c53ec95f0c93f31949380232c297dfe343ea34a831bae1
font_01_sfnt_off00011fb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FB3 10108 bytes
SHA-256: 059c33347eb40d8b382845d30d2629db33cd0fabf3498e1fa4e343321beb5286