Malicious PDF — malware analysis report

Static analysis result for SHA-256 535b07e01c829aff…

MALICIOUS

PDF

75.7 KB Created: 2021-09-18 21:29:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: a5fd8c406a9b140271ab39be3524f35c SHA-1: 1895e54e3dfe7c1462f49b8af9c2e0b219875d0d SHA-256: 535b07e01c829afff814c496cf667356853749d82b85da2baa665ce56b5ebc73
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file that contains embedded JavaScript, indicating a potential for malicious execution. It also features a link farm pointing to compromised WordPress upload storage and other disposable hosting, suggesting an attempt to redirect users to malicious sites. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of its attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 6

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://mmagame.com/userfiles/file/monuxiragegizidekamolem.pdf In PDF document text
    • http://kronikarp.pl/ckfinder/userfiles/files/94943358006.pdfIn PDF document text
    • https://tomorrowhubs.com/upload/users/files/wiminogazovero.pdfIn PDF document text
    • http://majortaylorride.info/images/uploaded/file/ninolep.pdfIn PDF document text
    • http://rund.cz/UserFiles/File/37456558018.pdfIn PDF document text
    • http://studiorinaldibedin.eu/userfiles/files/lexaku.pdfIn PDF document text
    • http://www.og2c.com/images/file/12422732150.pdfIn PDF document text
    • http://www.photonics-science.com/ckfinder/userfiles/files/11640295058.pdfIn PDF document text
    • https://youxsoft.com/uploads/files/85474970181.pdfIn PDF document text
    • http://hnspkjx.com/d/files/samig.pdfIn PDF document text
    • http://villaturri.it/wp-content/plugins/formcraft/file-upload/server/content/files/16133fd2d0a0f0---jojepazabizitobewij.pdfIn PDF document text
    • http://www.sainteuphrasia.com/www/js/ckfinder/userfiles/files/89181393482.pdfIn PDF document text
    • http://osmed.cz/app/webroot/files/files/40155962247.pdfIn PDF document text
    • https://sellos-mecanicos.com/wp-content/plugins/super-forms/uploads/php/files/83c535fac26ac7b7997255c24c386956/39564046138.pdfIn PDF document text
    • https://cooperadora.grupocreartel.com/documentos/archivos/65422923231.pdfIn PDF document text
    • https://fatheragneliti.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fff7c6f657---kidiwewurepomame.pdfIn PDF document text
    • https://nevjegyzek.eu/uploads/file/fokerevoxujawefatufat.pdfIn PDF document text
    • http://basketaci.cz/UserFiles/File/wizujeliwokukutorujub.pdfIn PDF document text
    • http://muntepa.com/userfiles/files/91487597078.pdfIn PDF document text
    • https://viceda.com/userfiles/file/zazeronozepobuduraj.pdfIn PDF document text
    • http://cmrivestimenti.com/userfiles/files/tisezusuk.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=text+messages+not+received+on+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_off0000c39d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC39D 17448 bytes
SHA-256: 5af6677ee0e9be86506a0068df541df0b4111713d50918bf035c081b92156e61
font_01_sfnt_off0000f023.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF023 10796 bytes
SHA-256: 6be7ba8afc368f7a8b40f89acbc22da8d42bb2c6113e40f1cc6409ef1009904c
font_02_sfnt_off000108e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108E5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1