Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c21efd613514b1e…

MALICIOUS

PDF

106.4 KB Created: 2021-08-14 19:49:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 10808746793fbcc55455452603acc125 SHA-1: e79689a2280d3eff094e76405a0226635083d15f SHA-256: 4c21efd613514b1e5c07e224d2f0b1e8b41a081ffb0a3933fa2f00a46e9271eb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected by ClamAV as Pdf.Phishing.Trojan and ML classifiers indicated a high probability of maliciousness. It contains a link farm pointing to multiple compromised WordPress sites and other domains, suggesting an attempt to distribute malicious content or phish users. The presence of embedded URLs and the nature of the heuristics indicate a likely spearphishing attachment used to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9918

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://www.lindopoint.it/wp-content/plugins/super-forms/uploads/php/files/032fbf77996e97bec716aa5eebcd63b0/dimosubegufun.pdf In PDF document text
    • https://electrabicycles.pl/app/webroot/uploads/file/1621202718427.pdfIn PDF document text
    • https://gberwanda.com/gbe/useruploads/blogs/files/guzukepuzuramujunuje.pdfIn PDF document text
    • https://kanalprofi.at/UserFiles/file/nulejutavagoxavebolivep.pdfIn PDF document text
    • http://jimigubellifoundation.org/clients/f/f9/f96c94eea877db95ad0a8b6fd709b1ed/File/jisixipemonutavog.pdfIn PDF document text
    • https://benchmarktransitions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c64235e7647---61774334211.pdfIn PDF document text
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160bce2db7e3da---56539087076.pdfIn PDF document text
    • http://inbjnews.com/data/cheditor/0603/files/janunixakelatojekos.pdfIn PDF document text
    • http://sam-global.info/files/file/xawusiben.pdfIn PDF document text
    • http://arcomproltd.com/userfiles/file/rirefejegabozewe.pdfIn PDF document text
    • https://estigotours.com/wp-content/plugins/super-forms/uploads/php/files/6f5030d144e4325b08b564e7ee773ea9/tujaleboboxizus.pdfIn PDF document text
    • http://www.danvillern.com/wp-content/plugins/super-forms/uploads/php/files/c393mjub4dchudqhuj5o9peqn0/46388675920.pdfIn PDF document text
    • http://penoplex24.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608010dc4e763---24011547450.pdfIn PDF document text
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a4b4d21c39---13485527630.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608208b449cf0---demuledoxutidomenulep.pdfIn PDF document text
    • http://skolky.info/foto/images/file/96356787339.pdfIn PDF document text
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160aa043334594---levudo.pdfIn PDF document text
    • https://decoveinvestment.com/userfiles/file/18184185641.pdfIn PDF document text
    • https://lifo-sea.com/ckfinder/userfiles/files/50846823690.pdfIn PDF document text
    • https://gbeequestriansurfaces.com/wp-content/plugins/super-forms/uploads/php/files/5agrhjopcv0oekgdad0lmk8vn6/foxorizizoreviponemab.pdfIn PDF document text
    • http://hnkingdee.cn/Files/file/20216263328.pdfIn PDF document text
    • http://romanakladatelstvi.cz/userfiles/file/sirolu.pdfIn PDF document text
    • http://www.emporiocaritaspisa.it/wordpress/wp-content/plugins/formcraft/file-upload/server/content/files/160c8a0b227a7b---3724326435.pdfIn PDF document text
    • https://psfund.org/public/uploads/files/cms_files/61209899182.pdfIn PDF document text
    • http://oecschool.com/userfiles/file/sijuvivijufojemagixew.pdfIn PDF document text
    • http://banglatalkies.com/dynamic-images/cms/file/kakemewusixojegijarimen.pdfIn PDF document text
    • http://udelimpa.es/ckfinder/userfiles/files/gurotor.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=algebra+1+multi+step+equations+with+fractions+worksheetPDF 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_off000136a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136A6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00014ebd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14EBD 11524 bytes
SHA-256: 378d925fcb86ef029629d896f93e1319b0c0b148aeba5e5a239cb0f698a82405
font_02_sfnt_off00016979.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16979 18488 bytes
SHA-256: 6c9cb7e6818272a61ad77f476f9e08adb0c25da95db67a5ce4a72abe177b2b30