Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b50bd640e94b614…

MALICIOUS

PDF

73.6 KB Created: 2021-09-08 01:00:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 3226231f56d6617a1abac5739791be47 SHA-1: 7c3e31ea05c71a50d06d86dc6918eb7aea45579d SHA-256: 1b50bd640e94b61445f3f60622674935862e513ff576380106301ce2862ca1fe
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, suggesting a link farm or phishing lure. The presence of PDF_URI and EMBEDDED_URL heuristics indicates the document attempts to redirect users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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 http://hunting.kg/userfiles/file/85749657765.pdf In PDF document text
    • http://allprintusa.com/admin/images/file/38683155154.pdfIn PDF document text
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/ehl1fpvuc45ikkfk22ok8c1k16/18226623913.pdfIn PDF document text
    • http://thuephotocopytaihanoi.com/upload/files/85066260981.pdfIn PDF document text
    • https://vienhung.com/webroot/img/files/nafotovigunutunesogalogiz.pdfIn PDF document text
    • http://sh8ke.com/wp-content/plugins/formcraft/file-upload/server/content/files/160760d3834640---zopapizaxajopexeboro.pdfIn PDF document text
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1608d628a9be62---96111717869.pdfIn PDF document text
    • http://dentherapia.hu/files/file/72689937582.pdfIn PDF document text
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/2dde7c04642f218f456bd2de0e0840b6/gofizawurufow.pdfIn PDF document text
    • http://cavusofis.com/images_upload/files/venanekamumetemedod.pdfIn PDF document text
    • https://cleaner.pl/userfiles/file/58695228395.pdfIn PDF document text
    • http://machinegroup.ru/img/outer/files/26230165119.pdfIn PDF document text
    • http://iehyun.com/editorupload/file/giwuwa.pdfIn PDF document text
    • http://miyisz.com/mingyi/images/userfiles/file/67668604238.pdfIn PDF document text
    • http://2ds-creations.fr/userfiles/file/dokugimumeredakagodinus.pdfIn PDF document text
    • http://sostrevalli.it/userfiles/files/963025886.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abf9ffacf95---kelenoxizovudusilaxi.pdfIn PDF document text
    • https://bokaichenyu.com/upload/files/91395556554.pdfIn PDF document text
    • http://vietxetai.com/wp-content/plugins/super-forms/uploads/php/files/pd87dh3lor2s15dbk1k2obd15t/ketax.pdfIn PDF document text
    • http://oticonshop.net/ckfinder/userfiles/files/75098976406.pdfIn PDF document text
    • http://ytlcases.com/userfiles/file/46240272363.pdfIn PDF document text
    • https://catwalkdogcome.com/editor_upload_image/file/buluxebolule.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=linear+programming+worksheet+tesPDF link annotation
    • 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_off0000bc2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC2C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d443.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD443 10788 bytes
SHA-256: 5f52eeaf1bc5817f63a8a4f0b78cb8993562f7665c15b7fb5d30f04fd4f8429f
font_02_sfnt_off0000ecfb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECFB 17192 bytes
SHA-256: d9b174fcf311661814384e4782dec9ad95524a2d947a83f3b0b3821ac04225cd