Malicious PDF — malware analysis report

Static analysis result for SHA-256 74ef3ab15d8be44d…

MALICIOUS

PDF

83.5 KB Created: 2021-09-01 18:09:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 1534d061842337b23e94cf7ecb904c36 SHA-1: 1b9101a68597a730ddb74b9113daded8bda43b5e SHA-256: 74ef3ab15d8be44d512720c2bee86c2e3d3df81e0e952cd7f93a1e6c9089d25f
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised WordPress sites or disposable domains, suggesting a link farm designed to lead users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. No scripts were extracted, and the document body was unreadable, but the URL analysis and heuristic firings are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://coretry.ru/uplcv?utm_term=how+to+find+absolute+maxima PDF link annotation
    • https://prtl.pl/userfiles/file/fudawufese.pdfIn PDF document text
    • https://grahampropertytax.com/wp-content/plugins/super-forms/uploads/php/files/151b598e4767634c3c0eb6d0dcc59be1/81583602722.pdfIn PDF document text
    • https://www.olympusnorge.no/wp-content/plugins/super-forms/uploads/php/files/6tjtefagfs7dpdfkn2q6n72hlo/woxelezijifen.pdfIn PDF document text
    • http://kursadowicz.pl/Upload/file/42501768872.pdfIn PDF document text
    • http://caythuocdangian.net/images/files/kidamevuvodisaw.pdfIn PDF document text
    • http://extrastyle.ee/ckfinder/userfiles/files/menaxoveb.pdfIn PDF document text
    • http://ahkjt.com/upfile/file/94729624241.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b505263fdcf---suzapaposo.pdfIn PDF document text
    • https://cokhivietuc.com/img-vietuc/files/22197676020.pdfIn PDF document text
    • http://petra-dario.info/upload/datoteke/18270235407.pdfIn PDF document text
    • http://www.bash.cl/media/file/bovirovana.pdfIn PDF document text
    • https://championsforchildren.org/wp-content/plugins/super-forms/uploads/php/files/38f974345b85c30f0f054cf43ce66431/nelaxuxexasi.pdfIn PDF document text
    • https://coaching-jk-academic.com/ckfinder/userfiles/files/65366940966.pdfIn PDF document text
    • http://poorclarescork.ie/images/42599044479.pdfIn PDF document text
    • https://hogies.com/includes/template/uploads/file/puxijarekatusixa.pdfIn PDF document text
    • http://niengrangchuyensau.com/upload/contentFile/file/rugimekomil.pdfIn PDF document text
    • http://clasesholandes.com/userfiles/file/69250486968.pdfIn PDF document text
    • http://africansafaris-spain.com/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/69421046571.pdfIn PDF document text
    • http://akicgiyim.com/userfiles/file/16633133088.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/4b85bf86ff671db8499ef02e398bc713/denubafogiriwuti.pdfIn PDF document text
    • http://kimbuunguyen.com/uploads/userfiles/file/60570094605.pdfIn PDF document text
    • http://grapevinewinerytrail.com/clients/876125/File/12529022056.pdfIn PDF document text
    • http://kirakuramen.com/uploads/files/mizunozekisakiled.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_off0000dd28.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD28 10836 bytes
SHA-256: 4fb8d9af88af820a0776365ae7c436abd116024e0bf7a268884072dc289ce446
font_01_sfnt_off0000f62a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF62A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010e3c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E3C 17972 bytes
SHA-256: 1f66baa656411d08b95bb05ec7b777e02cfa2b6bec659e802480e3b2819874e5