Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5bbdcabf105654e…

MALICIOUS

PDF

79.6 KB Created: 2021-06-15 23:34:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-24
MD5: 270aac138b1668cfb8611b7b99ff8bfe SHA-1: ae380a863ea958fbf65e8771e570f9a82554c69d SHA-256: c5bbdcabf105654efc142500f1ff138c32aaf78ce47fefd0fef5c1d7202fa6ac
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 0.9997

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://krisoc.ru/uplcv?utm_term=angry+birds+star+wars+2+unlock+code+pc PDF link annotation
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b7840a8b581---fatisiraxawir.pdfIn PDF document text
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/780e12518006850b5108c04a708fe9f3/dezejosatametewito.pdfIn PDF document text
    • http://www.belladermeestetica.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160afe646ab4c1---78452963860.pdfIn PDF document text
    • http://accronline.com/userfiles/file/lujewiragilidoz.pdfIn PDF document text
    • https://wegofa.com/userfiles/file/komivowaruw.pdfIn PDF document text
    • http://muskogeeroughers1967.com/clients/9/98/9899c641331876fb313f08ec475a0443/File/sepurarugidexebilano.pdfIn PDF document text
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d1dfd54a4a---murolepitaxofu.pdfIn PDF document text
    • http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/1606fffe6a46b0---pigeme.pdfIn PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/fed5e8e8be7525f9fa401fea5195ca08/54732462186.pdfIn PDF document text
    • http://www.northeastmarquees.com/wp-content/plugins/super-forms/uploads/php/files/02e48f2722711995d9e2d283f30680ab/80295010871.pdfIn PDF document text
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/40a7aadd611a8b1f800973f19cd83b4e/43893894675.pdfIn PDF document text
    • https://ecef-groupe.com/wp-content/plugins/super-forms/uploads/php/files/4g400jhodbr1dlasms5ei6ahe1/jidefubunatemegefep.pdfIn PDF document text
    • https://ltgtrends.com/wp-content/plugins/super-forms/uploads/php/files/cde34ef0f5c3aba34ab2c2af8c7adb7c/13532731529.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_off0000f53d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF53D 5760 bytes
SHA-256: a94f645712f2fefd72a146ea3b449c0571bce323ae7c378e887e7041c78435af
font_01_sfnt_off00010908.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10908 12788 bytes
SHA-256: e12ba656a770327d497a4d50d819b9147fe2ae0db7f396e9ae1d9be4c77e09d0