Malicious PDF — malware analysis report

Static analysis result for SHA-256 b78912cdc669376a…

MALICIOUS

PDF

90.0 KB Created: 2021-07-02 02:57:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: e72a294fddc59f76b78bf376d1d53dc2 SHA-1: 6e643e15275e75c2629a8c83896d1c811a03a769 SHA-256: b78912cdc669376a89b4aa6665bb502b9169e39872339f866b641c6b9ed1167f
156 Risk Score

Malware Insights

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

The PDF document was flagged by multiple heuristics as a link farm, with many URLs pointing to compromised CMS uploads and disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to phish users or lead them to further malware. The document body is heavily obfuscated and contains no readable text, suggesting it's designed purely to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://fastcomputer.vn/wp-content/plugins/super-forms/uploads/php/files/712072584b03674d351bdebc673b4048/9972029839.pdf In PDF document text
    • http://files.ibiza-ferien.de/file/36485361846.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/dobdcpdtscjqmbed73e8667q57/10141473788.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608d541edffc5---32306576614.pdfIn PDF document text
    • http://autoscuolecasetta.it/userfiles/files/nemuzojumupuwujo.pdfIn PDF document text
    • https://koffiewarenhuis.nl/app/webroot/files/userfiles/files/36240260110.pdfIn PDF document text
    • https://mumegram.com/userfiles/file/daruziduti.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/1609692148a35d---mabawexofamererereb.pdfIn PDF document text
    • http://abwingsmd.com/uploads/files/kobovunewobudinaz.pdfIn PDF document text
    • https://marksiegeldds.com/wp-content/plugins/super-forms/uploads/php/files/191dadc05cdae0708f2c41d80aaaee10/25234796222.pdfIn PDF document text
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1607ebfbe419cb---lutazin.pdfIn PDF document text
    • http://sskj.pl/userfiles/file/luxuxezolinu.pdfIn PDF document text
    • http://skylineidaho69.com/clients/c/c7/c7306e0a9cc1d421caefa9c307ca601f/File/woresejewekokadiral.pdfIn PDF document text
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609214b3ac540---lanemiwakotipewesa.pdfIn PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16081b6e6cad93---22478484060.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16095d83cc681a---zenofujano.pdfIn PDF document text
    • http://accronline.com/userfiles/file/rafovis.pdfIn PDF document text
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607a6f08eb0ce---vewoluwu.pdfIn PDF document text
    • http://www.dismaplant.com/ckfinder/userfiles/files/82311927558.pdfIn PDF document text
    • http://vorne-sitzen.eu/pcms/content/file/waxuxibelasunisos.pdfIn PDF document text
    • http://studiorumeo.it/userfiles/files/nimozaxegok.pdfIn PDF document text
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607902bc333de---pirugivedomuzebevo.pdfIn PDF document text
    • http://aivieksteslaivas.lv/userfiles/file/nibipoki.pdfIn PDF document text
    • https://aadhaarretail.com/administrator/imagetemp/file/lelina.pdfIn PDF document text
    • https://alfa-pechati.ru/wp-content/plugins/super-forms/uploads/php/files/e22a5f650c8039fd9c81841bf2ab501a/nisawojosulozemipowumim.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=the+different+types+of+figurative+languagePDF 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_off0000fb5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB5F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011371.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11371 17416 bytes
SHA-256: 901fb173112a4b34104b151a03754e80f020dd54e678935ad724201e5985551d
font_02_sfnt_off000140ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x140FF 11020 bytes
SHA-256: 032dac32e9e1cee379ab15d59d6e30209d106d0ab5644483f5939152c8d0451a