Malicious PDF — malware analysis report

Static analysis result for SHA-256 c6cf789df66d2826…

MALICIOUS

PDF

76.4 KB Created: 2021-09-05 07:50:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 9158d1e2cbe38a7bc21eec4f9a1ad7f6 SHA-1: 9afd2b68d9c4870371384667ca1ce3f0b45969ed SHA-256: c6cf789df66d2826b5669d6e94685a8131c6cf0e0548cd08d93a5b806740225b
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised CMS upload directories and disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://skyfestival.kr/ckfinder/userfiles/files/gulupinakexasusabezarevig.pdf In PDF document text
    • http://stembridgefamilyreunion.com/clients/0/0d/0db03be1a97f3028174cafb645c8c91f/File/koluviwetibunen.pdfIn PDF document text
    • https://scalper.ir/data/files/file/kexopow.pdfIn PDF document text
    • http://przychodnia-felinskiego.pl/uploads/editor/file/jirufinifapegepavogolot.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160f79a4c3945d---61514606544.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/160bab88e5baec---82593321304.pdfIn PDF document text
    • https://www.sudoku-cool.com/ckfinder/userfiles/files/nelemapexegowub.pdfIn PDF document text
    • http://mtreurope.com/ckfinder/userfiles/files/zenosidufovomud.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1610944697821e---8190111466.pdfIn PDF document text
    • http://artiguardia.pl/userfiles/file/bopuvu.pdfIn PDF document text
    • https://cevhertemizlik.com/userfiles/files/38178444339.pdfIn PDF document text
    • http://zoncmswebsitebeheer.nl/files/editor/file/najinowokonariborezede.pdfIn PDF document text
    • http://superpart.com/files/72853753042.pdfIn PDF document text
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160a8b8aa2b474---84701693585.pdfIn PDF document text
    • https://camerabentrenet.camerabentre.vn/ckfinder/userfiles/files/rirawuxuk.pdfIn PDF document text
    • http://hrudolf.com/userfiles/xarenikevufuneretixewomo.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/2ufedeaufehuk1ln6hii9kcjq1/fidowovomuziwipevan.pdfIn PDF document text
    • http://www.hollyskauaicondo.com/wp-content/plugins/formcraft/file-upload/server/content/files/161006fbf25b68---73530081657.pdfIn PDF document text
    • https://xn----7sbabak5acz7byau.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/65f718242cc9643c421357bded58b809/79230253031.pdfIn PDF document text
    • https://cald-lighting.com/wp-content/plugins/super-forms/uploads/php/files/925f8338ca10de61ff9f6a6791161d7e/7173589023.pdfIn PDF document text
    • https://xn----7sbbg1ddpkdc.xn--j1amh/uploads/files/fekaximadiwopexexa.pdfIn PDF document text
    • https://eminenceconstruction.ca/viking1/uploads/files/nodexajemoxixemi.pdfIn PDF document text
    • http://etcad.net/np/upfile/file/22130498776.pdfIn PDF document text
    • https://globalazeri.az/wp-content/plugins/super-forms/uploads/php/files/b28htpqehrchdu9vturarqe7n1/sinusidofasadorokodivopok.pdfIn PDF document text
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/1607e484f3664a---rugomolisofezatavur.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=buell+1125r+service+manual+downloadPDF 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_off0000c546.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC546 17068 bytes
SHA-256: 2b0e78e5210fe80f8806c182856ce4036ff63c9859d68a890af5adad4b9bb942
font_01_sfnt_off0000f155.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF155 11044 bytes
SHA-256: 7ada449787177ca863b8bb0ed4e7d691239425af1a6e59767973df03c6452682
font_02_sfnt_off00010b39.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B39 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1