Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3a8b57a09f8c6df…

MALICIOUS

PDF

88.1 KB Created: 2021-09-13 19:52:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 9632884f1dc63cb0ae9be6a243c24ecf SHA-1: 8f8307e44dd694a43c9a0d8b8a324560b6468788 SHA-256: b3a8b57a09f8c6df9629770d0470a74e7657e5bed12666f95a07dc1a81e550b9
166 Risk Score

Malware Insights

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

The PDF document was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. The 'SE_BROWSER_INSTALL_LURE' heuristic indicates the document's content is designed to trick users into installing malicious software by posing as a necessary browser update or extension. While no scripts were directly extracted, the PDF structure and embedded URLs suggest it is designed to lead the user to download and execute a malicious payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://uslugiinzynierskie.com/eurostyl/photos/file/lubipajute.pdf In PDF document text
    • http://webbuilders.com/files/file/begeguluraxepowegazelix.pdfIn PDF document text
    • https://jck.ro/userfiles/file/kegezik.pdfIn PDF document text
    • https://dottoridegregorio.it/public/file/34137433609.pdfIn PDF document text
    • http://resumesfromabove.com/userfiles/file/seripukegazetubebel.pdfIn PDF document text
    • https://www.gurgy.net/ckfinder/userfiles/files/61974032552.pdfIn PDF document text
    • https://malmospelmanslag.se/userfiles/file/lijonudotek.pdfIn PDF document text
    • http://kuryakyn.ru/userfiles/file/67247020218.pdfIn PDF document text
    • http://lnv-cnc.com/userfiles/file/sutonovegade.pdfIn PDF document text
    • https://digireg.lu/upload/nugifopiguwodavoxal.pdfIn PDF document text
    • http://iehyun.com/editorupload/file/nujugokegokuxoxizurefiwij.pdfIn PDF document text
    • http://101balkon.ru/upload/files/fegujemetumoruvurotig.pdfIn PDF document text
    • http://media-production.net/admin/ckfinder/userfiles/files/meduwozojigimov.pdfIn PDF document text
    • https://lifeteacher.tw/uploads/files/202109130801447964.pdfIn PDF document text
    • https://kfmaccounting.com/webroot/img/content/files/40069935306.pdfIn PDF document text
    • https://actioncoach.com.my/wp-content/plugins/formcraft/file-upload/server/content/files/161369c367c274---51258900098.pdfIn PDF document text
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613655c165ede---ruzufamexerawukig.pdfIn PDF document text
    • http://progettogeometra.it/userfiles/files/zexafezomufadunevodog.pdfIn PDF document text
    • https://fetogram.com/images/upload/files/67190134383.pdfIn PDF document text
    • https://etonbio.com/newsLetters/images/file/19267542021.pdfIn PDF document text
    • https://impeka.lt/components/com_mijoshop/opencart/image/data/files/gagosoxuboliga.pdfIn PDF document text
    • http://ssss-sangam.com/userfiles/file/dijijuga.pdfIn PDF document text
    • http://aguito.madteam.net/ckfinder/userfiles/files/wadubudewoxeviwurisideton.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=simulatore+di+android+per+pcPDF 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_off0000f24e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF24E 10684 bytes
SHA-256: f050ac80130623bfcc3841682feaf724c63919225e4f6a886461d8573aee5df0
font_01_sfnt_off00010abc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10ABC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000122ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122CE 18340 bytes
SHA-256: b900523d445cb4be4831f12c71b102ecc81d866af3ecbd0b9b059933e8b89da0