Malicious PDF — malware analysis report

Static analysis result for SHA-256 28f9134407b6bb51…

MALICIOUS

PDF

69.8 KB Created: 2021-09-24 23:56:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 92a1614500fe78ebd805dd6c68f75f8f SHA-1: 40e66c9d7124e667c9827f66f1b9045eaba0d06b SHA-256: 28f9134407b6bb510be09579ad1c6d721c612e655203b740c6184243b363b894
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm pointing to compromised CMS upload storage and disposable hosting, suggesting an attempt to distribute malicious content or phish users. The embedded URLs, while some are benign, are part of a larger pattern of redirection to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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 http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131fa81bf4d1---90769951039.pdf In PDF document text
    • https://998.geektic.com/geektic/files/90396127887.pdfIn PDF document text
    • https://tiemhoamo.com/data/dulieu/files/fulumipipofog.pdfIn PDF document text
    • https://faceless.me/userfiles/files/jibib.pdfIn PDF document text
    • http://studiomilano.eu/userfiles/files/rotanufixafelabu.pdfIn PDF document text
    • http://felixefontesadvogados.com.br/ckfinder/userfiles/files/37411483825.pdfIn PDF document text
    • https://szelvedojavitasmiskolc.hu/files/files/69433662367.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612eea7a67de5---poxexiti.pdfIn PDF document text
    • http://mebel-moscow.com/content/xuploadimages/file/vuzedoferopudijadokas.pdfIn PDF document text
    • https://get-insurance.in/ckfinder/userfiles/files/zubojufudap.pdfIn PDF document text
    • https://onderdurdu.com/upload/ckfinder/files/lifegefivademax.pdfIn PDF document text
    • http://pathtojanna.com/userfiles/files/66920176313.pdfIn PDF document text
    • http://multiseal.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/1613521f956eaf---sosubepivuzamiteneti.pdfIn PDF document text
    • http://modernplating.com/userfiles/file/wanorize.pdfIn PDF document text
    • https://aymexco.ro/ckfinder/userfiles/files/71596914896.pdfIn PDF document text
    • http://life-worldwide.org/assets/uploads/files/sigazarapasabikoju.pdfIn PDF document text
    • https://homeaestheticsllc.com/wp-content/plugins/super-forms/uploads/php/files/63376cb57ce3a974904369ba63a2a00e/falum.pdfIn PDF document text
    • http://dges.in/userfiles/file/77406912239.pdfIn PDF document text
    • http://unsersohn.com/images/file/zujofu.pdfIn PDF document text
    • http://zit-tech.com/userfiles/files/54394148201.pdfIn PDF document text
    • https://millvalley.com/wysiwygfiles/file/nudosajotivazepe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=how+to+update+system+apps+in+androidPDF 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_off0000afed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAFED 10796 bytes
SHA-256: c7f2ae343b9e96c77282f69a7601b2c552ca8bdd8c952d4e8a7f4bda8129e1a0
font_01_sfnt_off0000c8d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8D0 16008 bytes
SHA-256: 18745a3d41ebc602d8fe05c9082d3d75916f7d978ddf40cca39f3f52378997a0
font_02_sfnt_off0000f15d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF15D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1