Malicious PDF — malware analysis report

Static analysis result for SHA-256 879b6c3d89f8bcf7…

MALICIOUS

PDF

71.3 KB Created: 2021-09-15 17:50:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: b4ef5ee2d8543dd6c3e9d3c7c9b2d6f0 SHA-1: e2c4ca9837a579c9023da6446c8ab5af9108875e SHA-256: 879b6c3d89f8bcf731c6fb63529e0aa8da84d4e1108d1cfb13d87a3adcdc8713
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, and it contains embedded JavaScript. It also features a link farm pointing to compromised WordPress uploads and disposable hosting, suggesting an attempt to distribute further malicious content or phish users. The presence of JavaScript indicates potential for executing malicious code within the PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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 http://maydemtienvn.com/upload/files/voridime.pdf In PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/161309d720be87---bexudelajavibarobolitefi.pdfIn PDF document text
    • http://personnelstrategies.net/userfiles/file/13745782014.pdfIn PDF document text
    • https://ooo-kenk.ru/userfiles/file/zarebomirasowef.pdfIn PDF document text
    • http://garagehayashi.com/js/upload/files/fipavobimipururumiduju.pdfIn PDF document text
    • http://blevy.com/ckfinder/userfiles/files/pevevaromomezesusitug.pdfIn PDF document text
    • https://santa.my/images/users/00000000/files/69722995814.pdfIn PDF document text
    • http://akademibt.com/resimler/files/49746090423.pdfIn PDF document text
    • http://jamalcar.com/userfiles/file/73446373112.pdfIn PDF document text
    • https://hzautomatisering.nl/userfiles/file/vuzuvoxu.pdfIn PDF document text
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/6ca5084108d257c7b45fc9070d4f9c18/74565667653.pdfIn PDF document text
    • http://francescasciortino.it/userfiles/files/17487729002.pdfIn PDF document text
    • http://agataklimowska.pl/userfiles/file/riboxak.pdfIn PDF document text
    • https://voyageaventurenepal.com/upload/files/lomaxufegelawijogi.pdfIn PDF document text
    • https://linhquan-group.com/upload/ck/files/24018729399.pdfIn PDF document text
    • https://micsys.in/userfiles/file/fatapojepof.pdfIn PDF document text
    • http://pcccphucvinh.com/upload/files/60784488190.pdfIn PDF document text
    • https://www.marjojaspers.nl/ckfinder/userfiles/files/75057358817.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/f5abac46c1fcafee40b14d05e59f7280/puwujuxezadovagopipexug.pdfIn PDF document text
    • https://mithermomix.com.mx/wp-content/plugins/super-forms/uploads/php/files/aba0acc0132104fbfa01145d6a400bcd/54368778252.pdfIn PDF document text
    • http://weingut-suppan.at/files/bogovisulezikoberenivivat.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=how+to+add+imei+number+in+android+phonePDF 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_off0000b54b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB54B 16272 bytes
SHA-256: 8cb02c2eba5f908c415a3055caac14e9cc0fd5b6ddfea14457b72564c996af4e
font_01_sfnt_off0000df44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF44 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f75b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF75B 10760 bytes
SHA-256: b9a55522e2ab37e1492aa7af30131190deb0e517ef82c24b4fd2ac1976500414