Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5efe5c6540fcc53…

MALICIOUS

PDF

79.4 KB Created: 2021-05-28 17:42:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 4f7aa43f1ea5a8dba4ce9c6d086c462d SHA-1: 33ed7df51c644ea702ae6efa775634c59de2410c SHA-256: b5efe5c6540fcc532c19862e0a20a262ecbfd6fdd7ad8516e310497f499bb249
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites acting as link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body itself is heavily obfuscated and appears to contain junk data rather than a clear lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://archism.ru/uplcv?utm_term=juegos+hackeados+para+android+apk+2020+mediaf%25C4%25B1re PDF link annotation
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/d234ab27e8b2a79c5eb8681125667e90/7525193437.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16079080aee045---31756718032.pdfIn PDF document text
    • http://moreit.ch/productinfo/file/39087087332.pdfIn PDF document text
    • http://biotledlight.com/userfiles/file/%5C/lipiwadofugamaziradomaxi.pdfIn PDF document text
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16094de66ed1e2---84335021352.pdfIn PDF document text
    • https://ehblending.com/wp-content/plugins/super-forms/uploads/php/files/3370eabdaf6f1bc1997a28e873721fa4/46466106900.pdfIn PDF document text
    • http://petra-dario.info/upload/datoteke/11136621087.pdfIn PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dbb4b493e7---mimabu.pdfIn PDF document text
    • http://pvsystexperts.com/wp-content/plugins/super-forms/uploads/php/files/ipumchdf1t4vhefitjq8vf0ui0/ligafuno.pdfIn PDF document text
    • http://gingerwooddesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079303e34623---7961330597.pdfIn PDF document text
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/160737864a2f6e---daxarufo.pdfIn PDF document text
    • https://growlocals.com/wp-content/plugins/super-forms/uploads/php/files/f1f1188fc8f3e49f43309573b2070f1a/xuvuvokixizajum.pdfIn PDF document text
    • https://www.nobleorthodontic.com/wp-content/plugins/super-forms/uploads/php/files/5c28b91992af0af1781bf2a9332f29fe/4306204421.pdfIn PDF document text
    • https://biocoils.com/img/file/tofedefefubuku.pdfIn PDF document text
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16072401c68947---wakolupovimow.pdfIn PDF document text
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609041eb5c89f---mikufozulebuzedipoxeni.pdfIn PDF document text
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160870fdf18c81---sivonog.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn 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_off0000de50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE50 5896 bytes
SHA-256: 51ccecffd5741959b3a68422ffb9c12440fa9d06a7eba14392de9073f1d2a43f
font_01_sfnt_off0000f23f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF23F 11944 bytes
SHA-256: ec9a51e853c5fb9ecae9407e9dbc6f475e82b2518767df1243a9fefb82a8dda9
font_02_sfnt_off00011840.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11840 16204 bytes
SHA-256: c988415812f594187b0a0ed75dc52802e798e1695b49bd300f8412a65040a449