Malicious PDF — malware analysis report

Static analysis result for SHA-256 21ca7c7a8c2416de…

MALICIOUS

PDF

82.6 KB Created: 2021-09-19 09:00:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 0f4aafd1b9119b2583a011b54f9f7525 SHA-1: 6d081d740ce78b6cb6161d15fcee931a62d35d2e SHA-256: 21ca7c7a8c2416de56dd6b0b373a742ba898048d29d5ecc255d92341055c5cae
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to deliver second-stage payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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
  • 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 https://garglob.ru/uplcv?utm_term=resident+evil+3+android+espa%C3%B1ol PDF link annotation
    • http://agrostroi-proekt.ru/ckfinder/userfiles/files/maminelixolefizito.pdfIn PDF document text
    • https://caraudioshop.ro/mm/file/96602717897.pdfIn PDF document text
    • http://huemin.com/fckeditor/userfiles/file/wanikubazopidufogelim.pdfIn PDF document text
    • https://roarmysecurity.ro/mm/file/japedorejebu.pdfIn PDF document text
    • http://jatyn.cn/upfiles/202109/file/1631386897.pdfIn PDF document text
    • http://liavanhaeringen.nl/userfiles/files/vemuxajerobojir.pdfIn PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1612e9e2170699---wekekoxivugodisuko.pdfIn PDF document text
    • http://sirindhorn.net/upload/File/39111069063.pdfIn PDF document text
    • https://weeb.nu/userfiles/file/41211672003.pdfIn PDF document text
    • http://louisamerino.com/userfiles/file/42343448349.pdfIn PDF document text
    • https://alate.org/admin/fckeditor/editorfile/75370589599.pdfIn PDF document text
    • http://canadapremiumlubes.com/survey/userfiles/files/31977489141.pdfIn PDF document text
    • https://0900107678.com/upload/file/84799954795.pdfIn PDF document text
    • http://agilesolutions.in/uploads/tovope.pdfIn PDF document text
    • https://xn--interpeas-r6a.es/upload/files/83005616354.pdfIn PDF document text
    • http://bangtutrang.com/upload/files/nijodov.pdfIn PDF document text
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/161459aa314ce0---vitovopifopuviruzuko.pdfIn PDF document text
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/161445633e69fb---63844060657.pdfIn PDF document text
    • https://audit-advisers.com/userfiles/file/patogomozezaf.pdfIn PDF document text
    • http://re-media.ru/foto/ck/files/korufebodigesofok.pdfIn PDF document text
    • https://rakowka.pl/userfiles/file/2648140776.pdfIn PDF document text
    • http://virtuozi.ru/sites/all/sites/virtuozi.ru/files/37120040899.pdfIn PDF document text
    • https://bunianco.com/other_files/File/39286910483.pdfIn PDF document text
    • http://www.mbk-montage.nl/ckfinder/userfiles/files/xujanebejadovexifo.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d7ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7CA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000efdc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFDC 19400 bytes
SHA-256: c607746b1e2461e724a6c51628d73341e9b70f2c162eaa1a146f29ad99dad06e
font_02_sfnt_off000121c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121C7 10872 bytes
SHA-256: 174559f655d680367d87b3dd8bff641f079017f5ba8ad3022cb65b7d82275461