Malicious PDF — malware analysis report

Static analysis result for SHA-256 40564561c2e1c1ac…

MALICIOUS

PDF

58.0 KB Created: 2021-09-26 05:04:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 6a70a1f831b42165375578d9cd5a018e SHA-1: d7964d422bd807b0587fe620dba9b79fe201e9e9 SHA-256: 40564561c2e1c1ace015ecd69a9c8ff79f00d9037df9ec1f7d7ba23a182423c2
154 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, and the document body was unreadable, so the primary attack vector appears to be the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6508

Heuristics 5

  • 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
  • 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://cructi.ru/uplcv?utm_term=robinson+crusoe+text+pdf PDF link annotation
    • https://www.nickelmarket.co.za/includes/ckfinder/userfiles/files/22011559040.pdfIn PDF document text
    • http://shouce-image.kuchuancdn.com/Public/resource/files/semujixadajegaxotaj.pdfIn PDF document text
    • http://sinojjacob.com/userfiles/file/80901332036.pdfIn PDF document text
    • http://facilitymanagementassociates.com/survey/userfiles/files/lijogarugotidonetivisoxo.pdfIn PDF document text
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/161404d7904a17---53048853905.pdfIn PDF document text
    • http://lex.tj/img/file/51855318571.pdfIn PDF document text
    • https://latrinquette.com/upload/editor/file/vutesuxogezaga.pdfIn PDF document text
    • http://phrabat.net/UserFiles/File/tuxiju.pdfIn PDF document text
    • http://swancentive.com/cote_dor_import/admin/ckfinder/userfiles/files/zabudawe.pdfIn PDF document text
    • http://www.skk.com.hk/admin/ckfinder/userfiles/files/dasitoso.pdfIn PDF document text
    • https://rockeit.com/userfiles/file/41313510425.pdfIn PDF document text
    • https://preprodpcb.com/userfiles/files/16520662844.pdfIn PDF document text
    • https://minlinart.com/archive/upload/files/nisakipidenegasixabete.pdfIn PDF document text
    • http://xn--c1aejbdnke.xn--p1ai/admin/ckfinder/userfiles/files/letaxojowawizudotudafinum.pdfIn PDF document text
    • http://www.rosabrockenhaus.ch/ckfinder/userfiles/files/nijoruwopuwo.pdfIn PDF document text
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/16141b7872d221---86253656114.pdfIn PDF document text
    • http://terremeraude.com/userfiles/file/lawakakune.pdfIn PDF document text
    • http://vincityhomes.vn/wp-content/plugins/super-forms/uploads/php/files/bpfn7dtti65v8vonincrj32nmh/fosezetavesat.pdfIn PDF document text
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16140632a4d18b---59111674387.pdfIn PDF document text
    • https://www.mnogotrop.com/ckfinder/userfiles/files/29428277003.pdfIn PDF document text
    • http://amsasecretariat.fr/userfiles/file/31481748196.pdfIn PDF document text
    • http://leebyunghun.org/new/upload/board/files/nemapumilatutopa.pdfIn PDF document text
    • https://mimpishio2bet.net/contents/files/xaserapedopa.pdfIn PDF document text
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613caae341893---tazimekiwozosedesisedud.pdfIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b23d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB23D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ca54.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA54 10792 bytes
SHA-256: 54e4543538f38aa5f7f369f11c22d94af0dfb54d44924a356705f268d48febd7