Malicious PDF — malware analysis report

Static analysis result for SHA-256 00c51d5383ff8023…

MALICIOUS

PDF

84.8 KB Created: 2021-09-19 15:35:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 1b989e3a6e63d8243ef9efb6f28a6cfd SHA-1: 02a46bcf8415168e1b9fa6cf0944b7129c596c4d SHA-256: 00c51d5383ff80230f7aa08c3c8bf354a267108f636c6df7481c91043672bec7
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier indicating maliciousness. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests the document is designed as a link farm, pointing to numerous distinct hosts. While no scripts were explicitly extracted, the presence of embedded URLs and the overall structure indicate an attempt to redirect users to potentially malicious sites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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 https://pastelbuilders.com/userfiles/file/linorebe.pdf In PDF document text
    • https://drhuanghair.com/uploads/files/202109152004187897.pdfIn PDF document text
    • http://formpart.com/upload/ckfinder/files/22580796683.pdfIn PDF document text
    • http://www.springperfect.com/upload/finder/files/voxotatatoji.pdfIn PDF document text
    • http://nwatchonline.net/userfiles/file/zefalaf.pdfIn PDF document text
    • http://daming-school.com/userfiles/file/11551550602.pdfIn PDF document text
    • https://greenboo.vn/uploads/files/nezanoxosaxomukosipepu.pdfIn PDF document text
    • https://rzfmuhasebe.com/userfiles/file/texob.pdfIn PDF document text
    • https://energiadirect.pl/application/resources/ckfinder/userfiles/files/9652185008.pdfIn PDF document text
    • https://samirkumarpaul.com/ckfinder/userfiles/files/zujarabejitagiz.pdfIn PDF document text
    • https://pierreseche.fr/userfiles/file/36261029559.pdfIn PDF document text
    • http://floridadressyourhome.com/uploaded_files/userfiles/files/32156375408.pdfIn PDF document text
    • http://abyss.sk/userfiles/file/25905875878.pdfIn PDF document text
    • https://charterboatdeliverance.com/uploads/files/21222360219.pdfIn PDF document text
    • https://www.wizzfizz.com.au/application/third_party/ckfinder/userfiles/files/tabosorogajelumapesariwe.pdfIn PDF document text
    • http://zamdq.com/filespath/files/20210907174829.pdfIn PDF document text
    • https://www.zolmedis.lt/ckfinder/userfiles/files/nitenufojuto.pdfIn PDF document text
    • http://falcon.dk/sites/default/files/webfm/47111557438.pdfIn PDF document text
    • http://kengosushionlineorder.com/uploads/files/69023306541.pdfIn PDF document text
    • http://mtjjt.com/2013/upload/article/files/210907200144331589g7kx7.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613f874e4f0f9---18745342239.pdfIn PDF document text
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/161389cb2ca130---62197168512.pdfIn PDF document text
    • https://ngaa.org.au/application/third_party/ckfinder/userfiles/files/26794693196.pdfIn PDF document text
    • http://fajni3333.fun4two.pl/uploads/assets/file/91934663513.pdfIn PDF document text
    • http://hondasushi.com/uploads/files/58386436180.pdfIn PDF document text
    • http://31kouqiang.com/userfiles/file/1630805191.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=modded+jetpack+joyridePDF 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_off0000e4dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4DD 10516 bytes
SHA-256: 08e9a27c316de6d1a8ad905b40651e098a76863690e1fdfba94a472d29b3cceb
font_01_sfnt_off0000fcf7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCF7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011509.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11509 18464 bytes
SHA-256: f0fbe3dfe9ce1cfdc23c36e8524b3e2e3c31781cdf120289c4c3b671c54f3aaf