Malicious PDF — malware analysis report

Static analysis result for SHA-256 c24811870340550b…

MALICIOUS

PDF

77.1 KB Created: 2021-06-12 00:55:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-01
MD5: 98e21ed1be8e6e6bdd06e3aa51db1861 SHA-1: 94271c47f919d61d82f43c84e05995239ba5f392 SHA-256: c24811870340550b33955fc3cbdaeed705390d5ba0500cb4b95ca7134e93e482
164 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://crewmak.ru/uplcv?utm_term=apk+to+exe+converter+tool+free+download PDF link annotation
    • https://www.napariverinn.com/wp-content/plugins/super-forms/uploads/php/files/96a081e261553e76f3767e6218be0835/55624048969.pdfIn PDF document text
    • http://mattstergamer.com/wp-content/plugins/super-forms/uploads/php/files/ps66nfknh0oe7ncq8vsa568b21/rafagefesupaxa.pdfIn PDF document text
    • https://414movement.com/wp-content/plugins/super-forms/uploads/php/files/c743ee45969f53bf412b702279ddca43/76367599248.pdfIn PDF document text
    • https://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/44eec7b3e29e6c5e5dc89cf4f3bd1e7c/dasefuf.pdfIn PDF document text
    • https://afriqueitnews.com/wp-content/plugins/super-forms/uploads/php/files/2bf0bd441ae667227e01995fc5e658a7/76081882116.pdfIn PDF document text
    • http://weymouthhighschoolclassof62.com/clients/5/50/50fe23896e84432c97ff20d680692bb9/File/31092681377.pdfIn PDF document text
    • https://www.endthestigmacounselling.com/wp-content/plugins/super-forms/uploads/php/files/3gos6srvm6roqoe401e4c2k43t/20694284473.pdfIn PDF document text
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607c1f1cb5b54---mosibu.pdfIn PDF document text
    • https://rsun.pro/admin/ckfinder/userfiles/files/60700586647.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160779ee4176ca---batotexifa.pdfIn PDF document text
    • https://ethiquedevelopers.com/wp-content/plugins/super-forms/uploads/php/files/aa24fcf4aca8dc83cacb8426c90c5a5c/zeromikanibowififinufifa.pdfIn PDF document text
    • http://jjmcp.jp/userfiles/Image/file/52815816073.pdfIn PDF document text
    • https://arizonapoolcontractor.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ecd191f19e---savobazete.pdfIn PDF document text
    • http://zawayakw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160818199a45ca---17975911499.pdfIn PDF document text
    • https://prokoncept.hu/admin/blogfck/image/file/57972528203.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/160af94c7ba6a9---siwatavuzu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e715.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE715 5244 bytes
SHA-256: 5c9fe6a323d321a3ae1c83afd6f5b22f188addd3d70870a7cbc098ea759eac10
font_01_sfnt_off0000f91a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF91A 17560 bytes
SHA-256: f35b16866fc015322ccdfc18afee5ee1919c414c207bb9326c62e64659e8aa7b