Malicious PDF — malware analysis report

Static analysis result for SHA-256 f81b8a43ced3e812…

MALICIOUS

PDF

74.6 KB Created: 2021-09-05 07:25:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 23109d072e814915821197dbd5564d26 SHA-1: 96b583558378a290c0737d6f35eb8290fc54ced7 SHA-256: f81b8a43ced3e812fe40a5e596389a5d1fdbac4e1c616fd07a609c3184c3ae08
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links, many pointing to compromised WordPress upload directories, indicating a link farm designed to host or redirect to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links.

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://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/160ad8e599fd12---nelufebivukawasides.pdf In PDF document text
    • http://ustunongel.com/image/files/21239195208.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/1608df76010916---jizemejimis.pdfIn PDF document text
    • http://kentcliffordreunion.com/clients/a/aa/aa84b18e55fac3ff3c25336c5005d9e5/File/torepujorabikitivavebi.pdfIn PDF document text
    • https://solidpractise.com/files/userfiles/file/xunosomaxoxusifu.pdfIn PDF document text
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/c85d241543e6f2a771bcbb4312e8f111/bigoxelevoxejo.pdfIn PDF document text
    • http://easy-sleep24.de/shop/images/editorfiles/file/balibijenanixema.pdfIn PDF document text
    • https://celovechurch.org/wp-content/plugins/super-forms/uploads/php/files/08a5b18e521eb9524b7c0a720e90cf99/72222395357.pdfIn PDF document text
    • http://www.magicapro.it/wp-content/plugins/formcraft/file-upload/server/content/files/160914523e7dda---58254366484.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e94d208e64---86912121081.pdfIn PDF document text
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ee9b5d13e4---84175135320.pdfIn PDF document text
    • http://youandisagenix.com/ckfinder/userfiles/files/48496107590.pdfIn PDF document text
    • https://iaetindia.com/ckfinder/userfiles/files/wonisoguboliziru.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/16104ba05c7656---4701495441.pdfIn PDF document text
    • https://www.tifdip.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c837d4a457---wegefuzixevojufopuko.pdfIn PDF document text
    • http://tz5168.com/uploadfile/image/2021/06/12/file/20210612_100736_170.pdfIn PDF document text
    • http://f-kcc.jp/user_data/userfiles/files/42054438281.pdfIn PDF document text
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160be7df6aa561---37510772836.pdfIn PDF document text
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/160d7be4b7eab6---fovutagilejisol.pdfIn PDF document text
    • http://refinerlink.com/userfiles/file/xulab.pdfIn PDF document text
    • https://pakistanchristiancongress.org/userfiles/file/46762163859.pdfIn PDF document text
    • http://mcutech.net/upload/2021/07/file/16251488971666698421.pdfIn PDF document text
    • https://gservicepz.com/wp-content/plugins/super-forms/uploads/php/files/c470d67e7cbb90a5de88b2754227cff7/wofavidedazexel.pdfIn PDF document text
    • http://babyshelter.net/assets/upload/files/16359370764.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=inequalities+and+their+graphs+worksheet+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_off0000c26c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC26C 11152 bytes
SHA-256: a6a36c9c994ac66bf8bcfa959394e7d275169d39c6c572acbfb45657c76c895c
font_01_sfnt_off0000dbfb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBFB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f40d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF40D 15776 bytes
SHA-256: adafa1e5e1cc1f61d1b62d9036541625225456f87a28c36ebfbcbd62d809c6f4