Malicious PDF — malware analysis report

Static analysis result for SHA-256 256af3f22863c5b1…

MALICIOUS

PDF

88.5 KB Created: 2021-07-06 14:06:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a15b1bb506eae1f2e6d85d514db62db2 SHA-1: c6eae54c3fb4bfce23f6a966b1d84ec86b93e4cc SHA-256: 256af3f22863c5b1de8692269f6237cadbbcf1992b6fe83dfba63db51d6600ee
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a link farm with numerous URLs pointing to compromised WordPress sites and other disposable hosting. These links likely lead to further malicious content or exploits, as indicated by the ClamAV detection and ML classifier. The primary function appears to be redirecting users to potentially harmful external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://oniceh.ru/uplcv?utm_term=tetraamine+copper+sulphate+structure
    • http://www.k-24.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aaaa9333cb7---97433653315.pdf
    • http://aldara-latinoamerica.com/userfiles/file/moloziduvebir.pdf
    • http://pvsystreports.com/wp-content/plugins/super-forms/uploads/php/files/fi3e7r846fa88r940r75v2qg22/50105206306.pdf
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/1607be073c77d5---fofelibivetozotojap.pdf
    • http://www.danvillern.com/wp-content/plugins/super-forms/uploads/php/files/e7ec17ca96cd3b43e13f17214c896931/76606654590.pdf
    • https://binarbaidfabrication.com/public_html/userfiles/file/nexuwu.pdf
    • https://tidaksusah.com/contents//files/85274891022.pdf
    • https://bloomeng.com/uploads/jadanuvajufavigekeroru.pdf
    • http://forglass.sk/userfiles/file/67534775860.pdf
    • http://morethancars.nl/uploads/edytor/file/71682190910.pdf
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c98d58e875---doresezapofowigisixa.pdf
    • http://www.elitagida.com.tr/wp-content/plugins/super-forms/uploads/php/files/j7ot6jbirc157opva5srqi1666/73253289762.pdf
    • https://clubsportedinburgh.org/userfiles/files/fuvagafixiwowez.pdf
    • http://www.deadclan.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160d2781fdcd71---91773535805.pdf
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/049dbe95744129b886d019144c5ebc78/nananetotiwevovowibu.pdf
    • https://edu-mate.kr/_UploadFile/Images/file/xixodusofekedolis.pdf
    • http://szkolka-wiercioch.pl/files/file/51822649119.pdf
    • http://csc-028.com/userfiles/file/20210616004522_7vs915.pdf
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/160aac14f9309b---47839102855.pdf
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1606fdd81b7391---datusipununovenit.pdf
    • http://getawaynewzealand.co.nz/wp-content/plugins/formcraft/file-upload/server/content/files/160a2af8d8fd3d---59484678474.pdf
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/f234a41cc1aadba47e49061139b87775/51156420571.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f3a1.bin
bd54b18f90d647fae08154eb29508564406fe81d5790da04478f24d857128b33
pdf-font-stream PDF embedded font (sfnt) at offset 0xF3A1 10700 bytes
font_01_sfnt_off00010bf8.bin
b2cc58a37e30f2e60c6c4c241dbc31c87792a6e55039e4562bf6df4221ccdfcb
pdf-font-stream PDF embedded font (sfnt) at offset 0x10BF8 18264 bytes
font_02_sfnt_off00013c8f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13C8F 16792 bytes