Malicious PDF — malware analysis report

Static analysis result for SHA-256 c376c4f07b37addb…

MALICIOUS

PDF

93.1 KB Created: 2021-07-05 00:15:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 9481aaa8d28714bd74f586c46cfe1198 SHA-1: 37b93a08bb85eebb18d131b85ac3387dd71c6474 SHA-256: c376c4f07b37addbff1e863f267878355411aebc81e94c26f4233bc304ca9a5e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link farm pointing to multiple compromised WordPress sites, a common tactic for distributing phishing lures or malware. The ML classifier and ClamAV detection strongly indicate malicious intent. No scripts were extracted, but the presence of numerous external links hosted on compromised infrastructure is a significant indicator of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9927

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://prsnashville.com/wp-content/plugins/super-forms/uploads/php/files/0062b854b4e8d88201d7cefaad0bf518/koganajuxalulumonibo.pdf In PDF document text
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160796b4b9b542---77784004569.pdfIn PDF document text
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/rsbsf2trqr7v4vs4qi2j8bqc4u/sebowafowulonorofadebe.pdfIn PDF document text
    • https://elektrona.cz/files/file/37882865659.pdfIn PDF document text
    • http://doo-san.com/userfiles/file/20210629130856.pdfIn PDF document text
    • https://footballsod.com/images/ck-uploads/files/14130476784.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/k7ajr5q5oespmv286encbl4ts2/xerozofemasavuxebodiz.pdfIn PDF document text
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b8a6d07e20e---98287536204.pdfIn PDF document text
    • http://www.petercar0937494634.com/upload/img/files/73173855404.pdfIn PDF document text
    • https://www.breastcancerfoundation.in/wp-content/plugins/super-forms/uploads/php/files/778e43ebb647d0f07d430ea7a9befb57/gamijavanofe.pdfIn PDF document text
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/17d44da752ca8ac46799825efbe52269/nitoxo.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/e049a6c2fe872cb1e36fb27122d062b2/tuluzofuro.pdfIn PDF document text
    • https://regeneracion-capilar.com/wp-content/plugins/super-forms/uploads/php/files/739861f3d07a1ac7077aebeae486dffb/lowabulifidevovoxijuk.pdfIn PDF document text
    • https://aquafilling.com/userfiles/file/63205742295.pdfIn PDF document text
    • https://www.qbuildsoftware.com/wp-content/plugins/super-forms/uploads/php/files/6135018e37e031a0b0aef1c8ba20ae28/41992881716.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/1608d2e83dab65---82943950656.pdfIn PDF document text
    • https://bindazzled.com.au/wp-content/plugins/super-forms/uploads/php/files/13b834112168567bfd9536c652052ce1/demibojoxip.pdfIn PDF document text
    • http://gaziogluenerji.com/images_upload/files/48942102716.pdfIn PDF document text
    • https://estoniapools.com/contents//files/jereruvusilekufuda.pdfIn PDF document text
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/d5ba27009866940bb70028c712b27c90/wurokov.pdfIn PDF document text
    • http://beachfirebrands.com/userfiles/file/pasujobefuludaripefuwag.pdfIn PDF document text
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160c61afcec289---99172799532.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cdd0d38323e---15296322856.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=castlevania+curse+of+darkness+isaacPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f5dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5DC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010de9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DE9 3992 bytes
SHA-256: 546b85f359ca8173470a085f41c48a0a7b757b57a8ee0e8d2672676c6f0029e5
font_02_sfnt_off00011d99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D99 10760 bytes
SHA-256: f0eb75fd41295f937338c1ead6944274ede95b8f443ba81cbfa2dd334c9ee6b3
font_03_sfnt_off00013687.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13687 18440 bytes
SHA-256: 9712f3878e12467c7ad1ddb697b50226569f9c36859dfd6cad8d93052587ef1a