Malicious PDF — malware analysis report

Static analysis result for SHA-256 51d8e746b552d16a…

MALICIOUS

PDF

79.9 KB Created: 2021-09-13 14:35:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 77d498f2166cc3e41a0e9aba703d415c SHA-1: 8eb7092f37145c92802669c6684dccadb4436a8b SHA-256: 51d8e746b552d16a635d9f84809d1d2fea506bdf7afa7f572827837c3f57323b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The sample was detected as a malicious PDF by ClamAV and an ML classifier. It contains embedded JavaScript and a link farm pointing to multiple unknown URLs, suggesting it's designed to redirect users to malicious content. The presence of embedded JavaScript indicates an attempt to execute code within the PDF viewer.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • 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
  • 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://clubesquilacoma.com/uploads/files/95264927169.pdf In PDF document text
    • http://fqcycpa.com/jingkelun/userfiles/files/20210911090248.pdfIn PDF document text
    • http://www.depomatrial.com/file/widefapapubabekugopisa.pdfIn PDF document text
    • http://aybar-gallery.com/userfiles/files/59368232542.pdfIn PDF document text
    • http://praguynakorn.com/praguynakorn/picture/datapro/files/voperibelifagedigusir.pdfIn PDF document text
    • http://cnhhgj.com/upfiles/userfiles/file/ruvesike.pdfIn PDF document text
    • http://garageanything.com/js/upload/files/16324192014.pdfIn PDF document text
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/161310a0157b70---28197200955.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135e1a5e5c02---71062279978.pdfIn PDF document text
    • https://frisch.ro/files/file/67452625199.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/80867256402.pdfIn PDF document text
    • https://hinaweb.com/upload/file/89638676914.pdfIn PDF document text
    • http://100gastro.cz/soubory/files/96388890905.pdfIn PDF document text
    • http://www.thunderesp.com/ckfinder/ckfinder.htmlfiles/tevunoguzaguras.pdfIn PDF document text
    • http://chunmianxian.com/upfolder/e/files/20210902075154.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/ac0c8a55c294143c55b8d7ccca80aa5f/5922747192.pdfIn PDF document text
    • http://web5gstore.com/Files/files/96966604975.pdfIn PDF document text
    • http://cetinelektrik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1613f2efac9796---86154013632.pdfIn PDF document text
    • http://tanabuauto.com/js/upload/files/filenepodano.pdfIn PDF document text
    • http://lamachine.nl/userfiles/file/26260903444.pdfIn PDF document text
    • https://podimercrm.com/img/files/jubogedurubises.pdfIn PDF document text
    • http://villaturri.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613d1b15865bb---wogoje.pdfIn PDF document text
    • https://annekienlen.fr/imagesfile/gotinix.pdfIn PDF document text
    • http://mobitransjogja.com/files/88429594210.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=all+american+season+3+episode+2+free+onlinePDF 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_off0000d078.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD078 18540 bytes
SHA-256: 16fbd1708f2ff0d3b06b4560e793c7b0be7c100c3964896cb87cb681b2f5b3fe
font_01_sfnt_off00010046.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10046 10956 bytes
SHA-256: 6b128f6a04307361b154532f3eb117fbdd8601626a219d3e2c4d2cf24ecc404e
font_02_sfnt_off000119b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119B6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1