Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8c37da51135befe…

MALICIOUS

PDF

80.2 KB Created: 2021-09-13 12:13:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 2ea1df9ced0aaad2e0132d228939af17 SHA-1: 4d694c3b46e7a7cb819ea5e375a275644020f0b3 SHA-256: f8c37da51135befe4813e429e72ff0cc82bc311a569baf580d4ae984a6a4850a
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many hosted on disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is a common technique for exploiting PDF vulnerabilities or redirecting users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9933

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://smidgel.ru/uplcv?utm_term=mad+out+2+mod+apk PDF link annotation
    • http://superazs.ru/images/news/file/goduni.pdfIn PDF document text
    • https://cafemocion.com/userfiles/file/bakigazofedoxabejibujeboz.pdfIn PDF document text
    • http://tg-focus.ru/userfiles/files/sifisozapuvigadetoji.pdfIn PDF document text
    • https://munis-roquesalbes.cat/demo/vilalba/imatges/file/79553110910.pdfIn PDF document text
    • https://unicorn.mn/js/ckfinder/userfiles/files/lonuta.pdfIn PDF document text
    • https://debcopharma.com/userfiles/file/39335965700.pdfIn PDF document text
    • https://srinivasagroup.com/ci/userfiles/files/ganal.pdfIn PDF document text
    • https://bibliotheque-des-arts.com/ckfinder/userfiles/files/4708731101.pdfIn PDF document text
    • http://otvorene-srdce.sk/userfiles/file/lexuj.pdfIn PDF document text
    • https://avantkart.com/wp-content/plugins/super-forms/uploads/php/files/o0bbtkhbgcgrf73vrb9ovgu7a0/26663225884.pdfIn PDF document text
    • https://monamifrance.com/FileData/ckfinder/files/20210906_B6066085FEE0D03C.pdfIn PDF document text
    • http://vitajeans.com/ckfinder/userfiles/files/wowosur.pdfIn PDF document text
    • http://dangkykinhdoanhkiengiang.com/upload/ck/files/bivavimidujudadawup.pdfIn PDF document text
    • http://escrima-rlp.de/userfiles/file/5052307471.pdfIn PDF document text
    • https://mancomunidadvaldizarbe.com/userfiles/files/zotinumelewamatu.pdfIn PDF document text
    • http://jtg-antracyt.pl/files/file/favakapigupidivu.pdfIn PDF document text
    • http://sistersaviopublicschool.com/userfiles/file/zekajivazajazafolo.pdfIn PDF document text
    • https://photojet.bg/userfiles/file/17740449805.pdfIn PDF document text
    • https://eseninternational.com/uploads/files/73066347126.pdfIn PDF document text
    • http://akademibt.com/resimler/files/pebanezixogelisov.pdfIn PDF document text
    • https://postelezmasivu-ostrava.cz/ckfinder/userfiles/files/69402680342.pdfIn PDF document text
    • http://ksnjl.com/userfiles/files/dadenodakosalitira.pdfIn PDF document text
    • https://hkparkkonutlari.com/image/files/70916495057.pdfIn PDF document text
    • http://samuiluxurytravel.com/Uploads/file/47455860851.pdfIn PDF document text
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b8ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8CE 16524 bytes
SHA-256: 70fe72149f43c45349b4a754ee3ff63a59c173d4402520bc89b1ada931ab6217
font_01_sfnt_off0000cff7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFF7 20220 bytes
SHA-256: acf77229e3aa56b8c8eb220e8c98f5baee745a8a5d67198de2295bd9677e7db2
font_02_sfnt_off0001041e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1041E 10216 bytes
SHA-256: 71afcd67523df1dd005c1d47899d93fbaa34965aa070ae1c574ee4d009d18c56
font_03_sfnt_off00011b21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B21 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1