Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b5c21e7d7415e36…

MALICIOUS

PDF

70.5 KB Created: 2021-10-03 19:35:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: c8e93220d547aa68184009edd5aea57e SHA-1: 000c79cde47dfb098a3c641b9487172b363c729f SHA-256: 5b5c21e7d7415e36d5b01f9fb1d17c0e7fc62d9c3e82c9b73fd161d0141fb087
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads and disposable hosting, indicative of a link farm designed to obscure the ultimate destination. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery. While no scripts were extracted, the structure and URL patterns point towards a spearphishing attachment used to lure users to external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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.
  • 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://dolmalatrek.com/userfiles/file/tomafugelujifilukuzufowej.pdf In PDF document text
    • https://camphacement.vn/upload/files/75426683538.pdfIn PDF document text
    • https://118highschool.am/wp-content/plugins/super-forms/uploads/php/files/d6d33998974be251d3f94054b17e245f/gofosakamopidufabivisetez.pdfIn PDF document text
    • http://nuklearmedizin-amro.de/userfiles/file/sunerovubidedux.pdfIn PDF document text
    • https://www.jaegeraviation.com/ckfinder/userfiles/files/49375334702.pdfIn PDF document text
    • http://kovacsoltvaskerites.hu/images/file/jowepuketaselo.pdfIn PDF document text
    • https://mpressivelabels.com.au/application/third_party/ckfinder/userfiles/files/37349581690.pdfIn PDF document text
    • http://comicpapyrus.com/wp-content/plugins/super-forms/uploads/php/files/4e4ec7de5f4e2f70074297f8d4df05ff/tazurekos.pdfIn PDF document text
    • https://citrasas.com/ckfinder/userfiles/files/31815079879.pdfIn PDF document text
    • https://zhongzing.com/uploads/files/202109080638139493.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613e2904516ac---kinezagufisu.pdfIn PDF document text
    • https://marsanz.pl/uploads/fck/file/rafile.pdfIn PDF document text
    • https://europawindow.com/app/webroot/img/main_content/files/47198029556.pdfIn PDF document text
    • http://parzenica-bialka.pl/userfiles/files/xilafijigumexim.pdfIn PDF document text
    • https://5uempat.com/contents/files/55138657405.pdfIn PDF document text
    • http://marcobernini.it/userfiles/files/68651793475.pdfIn PDF document text
    • http://zygzak.eu/foto_dane/wysiwyg/File/51409309694.pdfIn PDF document text
    • https://ctners.com/ckfinder/userfiles/files/79250781724.pdfIn PDF document text
    • https://svarovanijelinek.cz/ckfinder/userfiles/files/dobosukolob.pdfIn PDF document text
    • https://itscebu.com/upload/file/20210923143514.pdfIn PDF document text
    • https://ceadersvalet.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d87bcb1191---53893080099.pdfIn PDF document text
    • http://zonwering-nederland.com/ckfinder/userfiles/files/kupumunikuzadi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=meaning+of+word+pervasivePDF 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_off0000b1e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1E5 16404 bytes
SHA-256: 9dd08da94ec716d61d2e8327f8379401bd3ae8355d14a98c177a2349c3677da4
font_01_sfnt_off0000dbbc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBBC 10676 bytes
SHA-256: d64cc7102f5e3019a0c00b74b0e5bc4ef85815caed7c544084ddbb12637bd8b6
font_02_sfnt_off0000f42a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF42A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1