Malicious PDF — malware analysis report

Static analysis result for SHA-256 c81937243597b929…

MALICIOUS

PDF

82.9 KB Created: 2021-09-23 06:22:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 0fc77b1c7365330393bc71645849b849 SHA-1: fa94876a7b7c66a7559a4bec034eb8c31a6575a6 SHA-256: c81937243597b92966fb8cc24131879109339471b075c2413e6d4eb6f94d563d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to various domains, many of which appear to be compromised or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' indicate a pattern of using these links for malicious redirection. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://infrive.ru/uplcv?utm_term=malala+yousafzai+autobiography+pdf PDF link annotation
    • http://jjkxmy.com/upload/files/202109030308054663.pdfIn PDF document text
    • http://anonelectronics.com/admin/fckeditor/editor/filemanager/connectors/php/upload_jpg/file/202109112155104863.pdfIn PDF document text
    • http://xn----9sbbnbtte4cyg.xn--p1ai/ckfinder/userfiles/files/33665016221.pdfIn PDF document text
    • https://wickedcheesy.com/images/file/34097390969.pdfIn PDF document text
    • http://www.libroparlatolions.it/backoffice/ckfinder/userfiles/files/tejefe.pdfIn PDF document text
    • http://studiotecnicomancini.eu/userfiles/files/susalipoled.pdfIn PDF document text
    • http://autosoftware.company/autoresponders_images/files/fasabesaruxidil.pdfIn PDF document text
    • http://fgsconsulta.com.br/ckfinder/uploads/userfiles/files/92570980245.pdfIn PDF document text
    • http://gizmakina.com/depo/sayfaresim/file/74242890203.pdfIn PDF document text
    • https://globalmediaminds.com/uploads/files/40070307793.pdfIn PDF document text
    • https://xn--psg-9lac.hu/files/files/50859421092.pdfIn PDF document text
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613dff5165940---beruvoniw.pdfIn PDF document text
    • http://www.addvanceo.info/userfiles/files/69494227047.pdfIn PDF document text
    • http://masterref.ru/editorfiles/file/refakizofasobibiribu.pdfIn PDF document text
    • https://adikketiga.com/contents/files/defamonuvujeterujuze.pdfIn PDF document text
    • http://the-bom.kr/upfile/files/87334952791.pdfIn PDF document text
    • http://fotografoenricogiampieri.it/userfiles/files/vekaligemubu.pdfIn PDF document text
    • http://www.galiantsolutions.com/emailimages/file/kozunezilu.pdfIn PDF document text
    • http://sh8ke.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613abcb9d7d96---61294441240.pdfIn PDF document text
    • http://nationalherbo.com/userfiles/file/kadaxizadozibupal.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613701b3f09fd---79467399647.pdfIn PDF document text
    • http://alptw.com/images/files/xukobubamaparusumin.pdfIn PDF document text
    • http://banghetretunhien.com/media/ftp/file/rudavenodemori.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_off0000d835.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD835 10948 bytes
SHA-256: 0ecb0c3561f33849de1db4938643980d13a73d8c89a52dcb0b3a7092c0658a81
font_01_sfnt_off0000f15b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF15B 20040 bytes
SHA-256: a8aec9a46e0c16f890c09eef7db4761ab0ac0c77d0ec234eeca627cc9ffe23a2
font_02_sfnt_off00012657.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12657 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1