Malicious PDF — malware analysis report

Static analysis result for SHA-256 9d90d4bdc2fe3d23…

MALICIOUS

PDF

73.8 KB Created: 2021-09-01 04:59:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 6d25f0995004da8c6c47944d184e85c7 SHA-1: 9ee587daaee7ee20830bfa1905ad69a0adf695df SHA-256: 9d90d4bdc2fe3d235346f381dbe2c48093bc71b9e7ca8946e6d502174219dab4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, with several heuristics indicating it functions as a link farm. Some of these links point to compromised CMS upload directories, suggesting a potential distribution point for malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 https://latework.cz/soubory/51595438703.pdf In PDF document text
    • http://dioceseofniranam.org/userfiles/file/30783103909.pdfIn PDF document text
    • http://mojahotels.com/ckfinder/userfiles/files/22036822824.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160b1f0d364f77---13158950611.pdfIn PDF document text
    • http://www.ks-klinika.ru/ckfinder/userfiles/files/puwapurerevunesuwev.pdfIn PDF document text
    • https://rfcorporation.net/wp-content/plugins/super-forms/uploads/php/files/caf700381e7d70d9b78563b914d2a869/bonakebebosu.pdfIn PDF document text
    • https://zazilha.com.mx/wp-content/plugins/super-forms/uploads/php/files/0886b14abb57f63b26922aa6169d16f0/77471429655.pdfIn PDF document text
    • https://cutletsmeat.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c734b22d8c---42496623581.pdfIn PDF document text
    • https://parvazyab.com/basefile/api203/files/wosukuwupozupesix.pdfIn PDF document text
    • https://lightspec.com/wp-content/plugins/super-forms/uploads/php/files/e5181c7229a268e02137cd1e0775f755/wutinufavemusinukapub.pdfIn PDF document text
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606f4f575d74f---57319897281.pdfIn PDF document text
    • http://technoculture.cz/admin/upload/file/notigulapatijetalok.pdfIn PDF document text
    • http://www.everhouse.lt/wp-content/plugins/formcraft/file-upload/server/content/files/160fb760130c8d---kituvibudakiloxajoki.pdfIn PDF document text
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/160768db8bc430---52279546537.pdfIn PDF document text
    • http://mikailang.net/userfiles/file/20210508085030_283474420.pdfIn PDF document text
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161266fc9c23c1---57631817845.pdfIn PDF document text
    • https://intrigantka.ru/images/userfiles/file/38885464966.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/i28hbsanmb838ijmnjgafh6nd2/23912504858.pdfIn PDF document text
    • http://asude.istanbul/ck_images/files/24504308878.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=create+your+own+future+pdf+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_off0000bc43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC43 17160 bytes
SHA-256: f3a553cfceb3359e0b593ab5bf5b81d66cd4b1a0608f5b68d171aa86eaa5fa8a
font_01_sfnt_off0000e8cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8CF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000100e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100E6 10564 bytes
SHA-256: 17fba5adf841d4aafd98a8bcb74001793606578c3a05955871bdeee387091bc7