Malicious PDF — malware analysis report

Static analysis result for SHA-256 a57220a6aefbc56b…

MALICIOUS

PDF

81.4 KB Created: 2021-09-21 07:11:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 10d3eba0dc59097fac63526d046da7b0 SHA-1: d7826615964d3229ee769cc46a9f7736d4e3c58b SHA-256: a57220a6aefbc56bed98571e5e70d13cf27163327f6d00a4d367f65bda7f4f04
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code. The sample also exhibits characteristics of a link farm, with numerous external URIs pointing to potentially compromised or disposable hosting sites. These elements suggest the PDF is designed to lure users to malicious destinations, likely for phishing or to download further malware. The ML classifier strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://cructi.ru/uplcv?utm_term=peliculas+completas+gratis+en+espa%C3%B1ol+nuevas PDF link annotation
    • http://ambulatorioveterinarioilprato.eu/userfiles/files/lodevusut.pdfIn PDF document text
    • http://greenhere.cn/upload/ckimg/files/202109132055328567.pdfIn PDF document text
    • http://testplanet.nl/uploads/files/37551905164.pdfIn PDF document text
    • http://www.ciesol.es/ckfinder/userfiles/files/gunasu.pdfIn PDF document text
    • https://xn--z4qq44i.xn--kpry57d/upload/actfiles/30367450764.pdfIn PDF document text
    • http://baaningdoi.com/file_media/file_image/file/kuwunaxamodi.pdfIn PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/161306f9d9dac9---3353908135.pdfIn PDF document text
    • http://g-shocktou.com/user_file/file/fifuxof.pdfIn PDF document text
    • http://matras-devison.ru/upload/file/xabinebafujas.pdfIn PDF document text
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16143de6dacfbe---89638424753.pdfIn PDF document text
    • http://piannocreativo.com/js/new/fckeditor/userfiles/file/24585169745.pdfIn PDF document text
    • http://jualumnitoronto.com/editor/uploadfiles/wabujefedusamopi.pdfIn PDF document text
    • https://celovechurch.org/wp-content/plugins/super-forms/uploads/php/files/e165e5fdad046ead2a337f554d5832b8/13762198953.pdfIn PDF document text
    • http://pc-driver.ru/userfiles/files/20210264020.pdfIn PDF document text
    • http://itfkarnataka.com/cvsprojects/SSK/Source/2.0.0/images/files/66483595155.pdfIn PDF document text
    • http://studio-castiglioni.com/userfiles/files/97651511285.pdfIn PDF document text
    • http://daiichihr.com/uploads/news_file/27356887096.pdfIn PDF document text
    • https://lightupalife.org.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16143d6b192c2f---luborewug.pdfIn PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/f56a6c5a6c1aaa10406ee29ae177154d/73847591687.pdfIn PDF document text
    • https://novahealthclinic.ca/userfiles/file/liragawotebi.pdfIn PDF document text
    • https://skywaynepal.com/userfiles/file/jiwilegamujunu.pdfIn PDF document text
    • https://softwebstar.com/shop/userfiles/file/87006043290.pdfIn PDF document text
    • http://haphadoor.com/upload/files/93950703310.pdfIn PDF document text
    • https://xn--80aaijz0c.xn--p1ai/ckfinder/userfiles/files/vugetutela.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_off0000d38a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD38A 18796 bytes
SHA-256: dbd41b13a891b0a4778d18744ae66d8758ef496ae8f788214b1c997aac4d0971
font_01_sfnt_off0001039f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1039F 11088 bytes
SHA-256: b674f06dcb942f9e2bd794e500b1974800fe7f59c989db52b631c37349935357
font_02_sfnt_off00011d44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D44 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1