Malicious PDF — malware analysis report

Static analysis result for SHA-256 39a27b91009dc85e…

MALICIOUS

PDF

69.5 KB Created: 2021-09-10 03:22:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 082be966f78e7eb43bc70aad18b2ff50 SHA-1: 4d3be30464b75464382e98d7a32746df4e0af0ea SHA-256: 39a27b91009dc85e49fda551b5e16272d0079ff4a48d4019640ef89e63a04da8
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to a link farm, as indicated by the PDF_SEO_DISPOSABLE_LINK_FARM heuristic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and embedded links are indicative of a malicious document, likely delivered via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://nexapos.com/upload/files/jufixasufufatosefidem.pdf In PDF document text
    • https://yuanfuconstruction.com/ckfinder/upload/files/zadufivugog.pdfIn PDF document text
    • https://xuanhongkhang.com/upload/files/93930725034.pdfIn PDF document text
    • https://inarsindbari.org/uploads/naledutuxirakej.pdfIn PDF document text
    • http://architettotoma.it/userfiles/files/41378824027.pdfIn PDF document text
    • https://apotekatia.ba/fajlovi/66095390969.pdfIn PDF document text
    • http://hotelrealerimini.it/userfiles/files/moburuwixaxeforunow.pdfIn PDF document text
    • http://firstcuwire.com/file_media/file_image/file/26759068269.pdfIn PDF document text
    • http://photou.cc/ckfinder/userfiles/files/94500666218.pdfIn PDF document text
    • http://quatanggiabao.com/images/uploads/files/74638388737.pdfIn PDF document text
    • http://intertexmedical.com/userfiles/files/poluwenisituvivolol.pdfIn PDF document text
    • http://open.ua/uploads/ckeditor/files/9003501489.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/fcd1b5151a99563c130bcdcae3bd8ac2/rogitobekonowuvejoloj.pdfIn PDF document text
    • https://giriconsultancy.com/content_files/files/29430072590.pdfIn PDF document text
    • http://rc-modeller.se/images/file///newubewaletasubupinovur.pdfIn PDF document text
    • https://masukpt1.com/contents/files/60864631143.pdfIn PDF document text
    • https://jjcfurnituremaker.com/userfiles/files/99632723979.pdfIn PDF document text
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/161344702dc7a9---zulub.pdfIn PDF document text
    • http://sahamit.net/userfiles/file/gizarulorinolil.pdfIn PDF document text
    • https://petrovsky14.ru/docs/files/49336114766.pdfIn PDF document text
    • http://88cpap.com/userfiles/files/43988478535.pdfIn PDF document text
    • http://fresh-j.info/images/uploadedimages/file/bopijo.pdfIn PDF document text
    • http://bjsddesign.com/filespath/files/20210903034923.pdfIn PDF document text
    • http://nenorm.com/files/files/jaxununobeto.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=turbo+vpn+full+crack+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_off0000b380.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB380 15080 bytes
SHA-256: bfaa944ce8f5ac50b6ec91b92077334bcef046e9a327b26a76f97e1d241a9856
font_01_sfnt_off0000d976.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD976 10344 bytes
SHA-256: 7da7e7f204d83292e86e06913f3201304123f9faecc303b7e9e500655a63d3f6
font_02_sfnt_off0000f0b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0B8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1