Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f042daf71a33081…

MALICIOUS

PDF

77.3 KB Created: 2021-06-12 11:54:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: a81db8218f309363a2358b6b5c671089 SHA-1: 2fc8181672dd5075545077ff448b290892ec589c SHA-256: 4f042daf71a33081270f8324db774ff3049e4c73fac299470bf35aa0e9658afd
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF document contains multiple embedded links, many pointing to compromised WordPress upload directories, suggesting a link farm designed to host malicious files. The presence of a download button lure and the ML classifier's high confidence score indicate a phishing or malware distribution attempt. The ClamAV detection further solidifies the malicious nature of this PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://ketchas.ru/uplcv?utm_term=instagram+plus+pro+mod+apk PDF link annotation
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607a191f293cb---62035640249.pdfIn PDF document text
    • http://fortlauderdalelimorental.net/wp-content/plugins/formcraft/file-upload/server/content/files/16082738af15ab---59422122715.pdfIn PDF document text
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160819d8e124ea---bokis.pdfIn PDF document text
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f7cbd9ca01---62969520956.pdfIn PDF document text
    • https://anzmrrn.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607d790ed3cfe---kiwarukawojedoluxebepeno.pdfIn PDF document text
    • http://sazjah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a70590bcd5---rovor.pdfIn PDF document text
    • https://primeodontorj.com/wp-content/plugins/super-forms/uploads/php/files/ae9534e9fcb7fc3469e0481420e73abd/25103170787.pdfIn PDF document text
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160b54b8880054---juxuvin.pdfIn PDF document text
    • http://mobilesamara.com/img/files/file/56835226686.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607a279b272b3---23007102736.pdfIn PDF document text
    • https://insights3.com/wp-content/plugins/super-forms/uploads/php/files/36fcfb0cb489c3cfbc86942613076407/talexexufebovemato.pdfIn PDF document text
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160b53856ed2ed---43174032891.pdfIn PDF document text
    • https://certifiedmoversinc.com/wp-content/plugins/super-forms/uploads/php/files/e3cd2cd23284c68ad06fa9256ed734f1/tiwolarizinukuwoj.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/3a6faql2gugf7dm0r11h17eko6/45982411878.pdfIn PDF document text
    • https://jclifeschools.org/wp-content/plugins/super-forms/uploads/php/files/7d04c0f682776a2b35632494cc1d306c/pulaf.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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e7d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7D8 5280 bytes
SHA-256: 094a2f6233644611d41984484df9d8af18b05952a413af91d7077c3a66b5ffbe
font_01_sfnt_off0000f9b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9B6 14940 bytes
SHA-256: 193ce6e37f867a0f1970956ff2b8d1383f892ddad4553fc4da4d7537f63594be