Malicious PDF — malware analysis report

Static analysis result for SHA-256 98225cbf0e39d568…

MALICIOUS

PDF

70.3 KB Created: 2021-09-25 03:52:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: af45e6bdf522113e447c796bb4882144 SHA-1: 09ccda2bbf0712f3c1bc9466d1bbab35ef0bdd91 SHA-256: 98225cbf0e39d56866368ec711b8327533a06c965ad8c00e575a7ef201c39387
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics indicate the PDF functions as a link farm, with many embedded URLs pointing to various domains, some of which are hosted on compromised CMS upload storage. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://karaokejdi.com/ckfinder/core/connector/php/upload/files/17749181009.pdf In PDF document text
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/1613b0736e7756---wubexubetumimefute.pdfIn PDF document text
    • https://globalcircle.club/userfiles/file/53608960588.pdfIn PDF document text
    • https://coastalstudio.com/images/main/file/ramukipewumaxunen.pdfIn PDF document text
    • http://ng-sons.com/userfiles/file/13803728024.pdfIn PDF document text
    • http://client.diffuse.info/files/bobazapakexatitu.pdfIn PDF document text
    • http://qunjl.com/userfiles/files/wulifujugakozupa.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/16132f5334d320---49938859918.pdfIn PDF document text
    • https://onutglen.com/caningest/images/file/37794313636.pdfIn PDF document text
    • https://armenia4d.com/contents/files/19445830317.pdfIn PDF document text
    • http://www.introspekta.si/ckfinder/ckeditor_uploaded_files/files/perolibusikajiwiravuxesap.pdfIn PDF document text
    • http://vagtteam.com/userfiles/Files/sabakozodu.pdfIn PDF document text
    • http://skybuildinfraprojects.com/uploads/92502707908.pdfIn PDF document text
    • https://comesa.com.pe/wp-content/plugins/super-forms/uploads/php/files/d6496eace0fd91045f3accd6e47b71e5/joxetodew.pdfIn PDF document text
    • https://giorgiosantinelli.it/file/90257892669.pdfIn PDF document text
    • http://hotelalbicia.com/userfiles/file/75798913874.pdfIn PDF document text
    • http://oguraclutch.cn/uploadfile/files/49545125373.pdfIn PDF document text
    • http://agierresrl.it/userfiles/files/63026749435.pdfIn PDF document text
    • http://rustproofingottawa.com/userfiles/file/53601443246.pdfIn PDF document text
    • https://radiosmile.hu/upload/file/91715233520.pdfIn PDF document text
    • http://kimhoatra.vn/upload/fckimagesfile/kerirusipitipeke.pdfIn PDF document text
    • https://zhansq.cn/upload/file/10306328263.pdfIn PDF document text
    • https://maydongy.com/wp-content/plugins/super-forms/uploads/php/files/67ifkf12ure7fmj7n7nu3q9of9/26043403095.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=android+programming+pptPDF link annotation
    • https://rt9.rspo.org/ckfinder/userfiles/files/33308789314.pdfIn PDF document text
    • 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_off0000b033.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB033 17276 bytes
SHA-256: c0f0260a86d8b5756251da8a2199aec781fffe18e42e8c1bf8344f00dce4ab5a
font_01_sfnt_off0000dc6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC6C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f483.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF483 10368 bytes
SHA-256: ea9a025790ef07c804cd9fada4174061f46b1bcbd47624a6b2c77b4c25480a7e

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