Malicious PDF — malware analysis report

Static analysis result for SHA-256 c51c4b4f3130d964…

MALICIOUS

PDF

71.1 KB Created: 2021-09-26 00:04:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: ec7469a29b34a984bc8c41094ed4de77 SHA-1: 5aef6640286d305803a67753b7a93ea57a1a17f1 SHA-256: c51c4b4f3130d964e8fb8e5a5bb7860098c72ac5ad1e2994242b90b0a4f894fc
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many pointing to disposable domains, indicative of a link farm. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic and the high number of unknown reputation URLs strongly suggest a malicious intent to redirect users. While no scripts were explicitly extracted, the nature of the link farm and the ClamAV detection ('Pdf.Phishing.Trojan') point towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://basyapiemlak.com/yukleme_klasoru/userfiles/file/91003525568.pdf In PDF document text
    • http://sibstroiexp.ru/userfiles/file/23847200829.pdfIn PDF document text
    • http://4bx.pl/public/file/17722724342.pdfIn PDF document text
    • https://hobbes-group.com/upload/files/39460724702.pdfIn PDF document text
    • http://araulmor.tel-cor.com/images/library/file/sexuwakur.pdfIn PDF document text
    • https://superchills.com/userfiles/file/fimudor.pdfIn PDF document text
    • https://betentour.com/sites/default/files/file/mexiwabupewapapekazib.pdfIn PDF document text
    • http://heorungminhphat.com/luutru/files/61787454807.pdfIn PDF document text
    • https://mamalight.net/business_school/uploads/file/8020909205.pdfIn PDF document text
    • http://ceramicaartisticamarsalese.it/userfiles/files/91620885611.pdfIn PDF document text
    • https://marblobaths.ph/app/webroot/img/files/41661417322.pdfIn PDF document text
    • http://tcihk.com/userfiles/fajet.pdfIn PDF document text
    • http://immobiliareborghi.com/userfiles/files/mobulix.pdfIn PDF document text
    • https://benqmusicworkshop.com/fupload/file/sonoza.pdfIn PDF document text
    • http://vpecargo.com/userfiles/file/pibatediwabug.pdfIn PDF document text
    • https://gpagroup.in/wp-content/plugins/formcraft/file-upload/server/content/files/1613808a649ac5---36217725594.pdfIn PDF document text
    • https://serviceelectric.ca/userfiles/file/16705403940.pdfIn PDF document text
    • http://www.dogwoodagility.nl/ckfinder/userfiles/files/90262950102.pdfIn PDF document text
    • http://websurin.net/UserFiles/File/dunuromazikezalinikobapi.pdfIn PDF document text
    • https://er-cardiff.com/eurostyl/photos/file/63582426228.pdfIn PDF document text
    • http://www.skup.it/wp-content/plugins/formcraft/file-upload/server/content/files/1614d805487ea7---wumewikoledevozedemim.pdfIn PDF document text
    • http://indago-rovigo.it/userfiles/files/86281412508.pdfIn PDF document text
    • http://daotaonhaccong.com/uploads/userfiles/file/jozuwapijekesofinagonup.pdfIn PDF document text
    • http://kipia-nn.ru/userfiles/file/wevigagejuruvupume.pdfIn PDF document text
    • https://drproperty.in/userfiles/file/jinokalivur.pdfIn PDF document text
    • http://boatmonies.com/uploads/files/11371869249.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=sync+outlook+mail+with+androidPDF 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_off0000b531.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB531 10804 bytes
SHA-256: e381e32f630ec1a9237fa891641e8a43e667005abcd2a02e424e9bfb9df29be2
font_01_sfnt_off0000cdf0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDF0 15920 bytes
SHA-256: ae945137f7bbd878b992ced278e147a7c29f40fb8c4be9f36d6b61888c1b0595
font_02_sfnt_off0000f66e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF66E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1