Malicious PDF — malware analysis report

Static analysis result for SHA-256 5cf45535f6bf7fba…

MALICIOUS

PDF

80.3 KB Created: 2021-09-17 13:52:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 32cade5a1ef0056792055eceacc7c69f SHA-1: 18d9f966596a280f76415e917fcfbaf7a2c6035c SHA-256: 5cf45535f6bf7fba48c1bcba50072b9fcd6e76bc8ebf2be447f4db6afd0452d4
66 Risk Score

Malware Insights

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

The PDF file was identified as malicious by an ML classifier with high confidence. It functions as a link farm, containing numerous embedded URLs pointing to external PDF files hosted on various domains. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for these links, suggesting an attempt to obscure malicious activity. While no scripts were extracted, the structure and numerous external links strongly suggest a malicious intent, likely to lure users to compromised or malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 4

  • 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://veganogle.es/uploads/ckfinder/files/fugetaporenofulutit.pdf In PDF document text
    • https://vantainoidia.vn/ci/userfiles/files/92792172479.pdfIn PDF document text
    • http://majortaylorride.info/images/uploaded/file/remugufaxawegirore.pdfIn PDF document text
    • https://onhimalayas.com/ckfinder/userfiles/files/99653547973.pdfIn PDF document text
    • https://rowanmkt.com/Uploads/ckfinder/userfiles/files/77177776998.pdfIn PDF document text
    • https://amigo-shop.105h.net/upload/files/biladuja.pdfIn PDF document text
    • https://bunianco.com/other_files/File/fejul.pdfIn PDF document text
    • http://caratow.nl/userfiles/file/mewawevotolus.pdfIn PDF document text
    • http://www.hon-ro.hu/userfiles/files/dewego.pdfIn PDF document text
    • http://inannamsao.com/uploads/files/6582699162.pdfIn PDF document text
    • http://npi-management.com/ressource/site-image/files/96489248768.pdfIn PDF document text
    • https://lochoanggia.com/upload/files/93328154429.pdfIn PDF document text
    • https://mccartha-cobb.com/userfiles/files/52082575934.pdfIn PDF document text
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613de073bf175---2916799533.pdfIn PDF document text
    • http://agrion.org/upload/fichier/kexudilutaroruj.pdfIn PDF document text
    • http://art-lan.ru/uploads/assets/file/96222137365.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d292c1a998---puroretejukakuwed.pdfIn PDF document text
    • http://worldnaturalfood.com/image/upload/File/84485077526.pdfIn PDF document text
    • http://futurepoolandspa.com/ckfinder/userfiles/files/lifezugigejawaxoliseputap.pdfIn PDF document text
    • https://ciar.vn/uploads/image/files/42365860309.pdfIn PDF document text
    • https://gionggiacam.com/ckfinder/userfiles/files/27338034602.pdfIn PDF document text
    • http://yugang360.com/upload_fck/file/2021-9-6/20210906135255864475.pdfIn PDF document text
    • https://narellesastro.com/userfiles/files/depudifujelafevi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=free+tubemate+download+apkPDF 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_off0000d589.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD589 10688 bytes
SHA-256: 5efb8b4ca4715fd04f5b6315744320ffd687457878878a2470f3cd23e9cba8a1
font_01_sfnt_off0000edd0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDD0 17764 bytes
SHA-256: ca1a9d7ce3c998372f90f541aaa9c5f6a9dbb6dc36a31bdb740807635e2670b5
font_02_sfnt_off00011baa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BAA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1