Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9b1cbe4f81cc4ef…

MALICIOUS

PDF

86.9 KB Created: 2021-07-03 09:35:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 509941dff62e75a0d8f55ce44df32949 SHA-1: cd34177e3bece0675a616b6ebb493c93c8b09512 SHA-256: b9b1cbe4f81cc4ef994af5d557cdc1c796163ffda9f2a2c0051f84515c27df29
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The file contains a link farm pointing to numerous compromised WordPress sites and disposable hosting, suggesting an attempt to distribute malicious content or conduct phishing. The presence of embedded URLs and the nature of the heuristics indicate that the document is designed to redirect users to external, potentially harmful, websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://crysiq.ru/uplcv?utm_term=how+many+0%27s+in+1+trillion PDF link annotation
    • https://harkakotony.hu/UserFiles/file/84426642470.pdfIn PDF document text
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b114bc73b7e---vevagivesaro.pdfIn PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bdaa9956a6b---99557942939.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/gsoeijgva5ls30a393s6f0b985/16978809136.pdfIn PDF document text
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/d0e41cd2d3e386cf460816be36e44142/32310348935.pdfIn PDF document text
    • https://www.ediliziaindustriale.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfceec09f90---75082051523.pdfIn PDF document text
    • http://daiichilogistics.com/uploads/news_file/nugajekiwovire.pdfIn PDF document text
    • http://hanboo.cn/Uploads/file/2021062117451770554.pdfIn PDF document text
    • https://malimbe.africa/wp-content/plugins/super-forms/uploads/php/files/747d66b0b97722f0227da3bb212d0421/28543799870.pdfIn PDF document text
    • https://www.hediyevideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160942b39b3be7---8897467221.pdfIn PDF document text
    • https://event-connections.net/wp-content/plugins/formcraft/file-upload/server/content/files/160816200782b1---54933030786.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071cff2d769c---80646684509.pdfIn PDF document text
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083c99de2ab0---40979125184.pdfIn PDF document text
    • https://impariant-club.ru/wp-content/plugins/super-forms/uploads/php/files/b2e2745015acc4587b02c7bb89e6429e/72972614571.pdfIn PDF document text
    • http://canxetaianhduc.com/images/file/zowav.pdfIn PDF document text
    • http://jirehenl.com/userfiles/file/071557094600.pdfIn PDF document text
    • https://www.cocochan.com.pk/wp-content/plugins/super-forms/uploads/php/files/e453563ead38561dc3272ff38f3796d2/robevorosuroleded.pdfIn PDF document text
    • https://viajespereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c03a1e74e99---mulufejatoj.pdfIn PDF document text
    • https://ajwatravel.com/wheelmarine/userfiles/file/bafudijikebofonug.pdfIn PDF document text
    • http://optimus.org.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607cca5da7ce6---94620775509.pdfIn PDF document text
    • http://allseasonsbanquet.com/clients/868236/File/numobenekugoxujifi.pdfIn PDF document text
    • https://elnativocoffee.com/silver/upload/files/rurekusuriso.pdfIn PDF document text
    • http://parkhighclassof60.com/clients/871169/File/denufibalawerezexivagivu.pdfIn PDF document text
    • https://mithermomix.com.mx/wp-content/plugins/super-forms/uploads/php/files/a3f661a7e7a9d549affcd2502da12129/13628403713.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/8ac5df8ac5d69ed9666f6cbdb02aa993/zuwifolimiritakori.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_off0000ee65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE65 10536 bytes
SHA-256: 53306dba3f3d559a5e9843b4c8b813f7c52f08ff24fadc9a34e16ebf53f48bf0
font_01_sfnt_off0001067c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1067C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011e8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E8E 17536 bytes
SHA-256: 7bec5cdc1f4217dded0c9b5d685caa47e23ee5c24baab3fcfa748d45e2b56e73