Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a731931fdb8f398…

MALICIOUS

PDF

88.7 KB Created: 2021-08-14 18:01:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 99371199231e7f973417c71c735942e5 SHA-1: dc381b91fbd2fcccd6ffb7aed8e735e82d9adc56 SHA-256: 8a731931fdb8f3988eff039c67c5b9e48adcc4de9855bf0aa1c626aa14ef4485
162 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript and a significant number of external URIs. These URIs are structured as a link farm, with many pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to obscure the ultimate destination. The embedded JavaScript likely facilitates the redirection or further payload delivery, contributing to the overall malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8417

Heuristics 6

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://infrive.ru/uplcv?utm_term=logical+reasoning+and+analytical+ability+syllabus+for+upsc PDF link annotation
    • http://gps-tw.com/CKEdit/upload/files/99422010574.pdfIn PDF document text
    • http://workcoop.org/fckeditor/userimages/file/20210619155130.pdfIn PDF document text
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/73cb439173b9a60f4d9246ef15743a92/lipuvanitosere.pdfIn PDF document text
    • https://polskieplytki.com/wp-content/plugins/super-forms/uploads/php/files/3be2dea7ac737c500ad4711ce083e4fa/7812518293.pdfIn PDF document text
    • https://xpress2.eu/ckfinder/userfiles/files/joxofalulevudusezaposovov.pdfIn PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160797c3f128fd---43594456016.pdfIn PDF document text
    • http://takeacode.net/user/d41d8cd98f00b204e9800998ecf8427e/file/41794512599.pdfIn PDF document text
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f2033447d4a---67943300595.pdfIn PDF document text
    • https://whatproperty.ng/ckfinder/userfiles/files/64578664571.pdfIn PDF document text
    • https://guijek.com/userfiles/file/dogeja.pdfIn PDF document text
    • https://www.la-providence-ehpad.fr/ckfinder/userfiles/files/wunebemuvoxorewa.pdfIn PDF document text
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6de3422f58---jusoroputukojavusitopi.pdfIn PDF document text
    • https://outsourcedbackoffice.co.uk/wp-content/plugins/super-forms/uploads/php/files/932d600673dd50153c999849d355caaa/58790779044.pdfIn PDF document text
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1606d083e56884---gobojubo.pdfIn PDF document text
    • http://www.realisthotel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cc775ee3079---sosotarubidujezupil.pdfIn PDF document text
    • https://humanistbeauty.com/wp-content/plugins/super-forms/uploads/php/files/7bkg5fn2cbnd6ajlav3nn9rr29/fumefopatijokirunoraja.pdfIn PDF document text
    • http://elementsgogreen.com/userfiles/file/zerevirinelavogal.pdfIn PDF document text
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5ec06692ca---94764931300.pdfIn PDF document text
    • https://wlao.on.ca/wp-content/plugins/super-forms/uploads/php/files/672c1bbc43167e7d7426935ae067344f/89434171745.pdfIn PDF document text
    • http://zhouzhuank.com/v15/Upload/file/20216201542105863.pdfIn PDF document text
    • https://slaterlighting.com/wp-content/plugins/super-forms/uploads/php/files/ba6a2bc938c69ec08674d7e0da38308c/47828706783.pdfIn PDF document text
    • http://maduraicaterers.com/app/webroot/js/ckfinder/userfiles/files/94505809807.pdfIn PDF document text
    • http://whkmradio.com/userfiles/file/6712410901.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_off0001112a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1112A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001293c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1293C 17960 bytes
SHA-256: 8ab08aeb3c3962636a844f52f25d9065b27cf72c4e6927f27ae3c11d8a759a71