Malicious PDF — malware analysis report

Static analysis result for SHA-256 900b94e57a6ddb38…

MALICIOUS

PDF

76.9 KB Created: 2021-06-10 21:41:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-26
MD5: ef04cd08da45cb06542f204f7c6519ec SHA-1: e21041c960187aaf11173f397de55c9d7e6beda1 SHA-256: 900b94e57a6ddb386c7a6369b5c54c8f4bf24a0230b32f33a2f6db3ebea05e73
156 Risk Score

Malware Insights

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

The PDF file contains numerous links pointing to compromised WordPress sites, suggesting it's part of a phishing or malware distribution campaign. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery. The presence of embedded URLs and the use of compromised CMS upload storage further support this assessment.

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://krisoc.ru/uplcv?utm_term=maleficent+2+free+movie+download PDF link annotation
    • http://delawaretravelmedicine.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086b826100f1---429151166.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608ace3d89a25---viwonunasepa.pdfIn PDF document text
    • https://lynnesnaturaltreats.com.au/wp-content/plugins/super-forms/uploads/php/files/f95cbfee0cc15c9ba8c5fbc1eec66743/59267864261.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/16072435895d7e---3340179753.pdfIn PDF document text
    • http://ontheedgeofnow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a7c64d0028---904891647.pdfIn PDF document text
    • https://toromecanicorodeo.com/files/18657300125.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1608bd57f54a53---58117847769.pdfIn PDF document text
    • https://drmiamiconnect.com/wp-content/plugins/super-forms/uploads/php/files/68421a88058df0ea84449a5514f779bd/29839203092.pdfIn PDF document text
    • http://wypelnienia.kratex.pl/wp-content/plugins/super-forms/uploads/php/files/48335eb1a72d9e7e2e2352043a8535c2/gujaxa.pdfIn PDF document text
    • http://bmcnx.com/userfiles/file/kuraxetovowoguvefaj.pdfIn PDF document text
    • http://branpc.in/ckfinder/userfiles/files/27832257429.pdfIn PDF document text
    • http://divorce-difficile.fr/userfiles/file/27400393165.pdfIn PDF document text
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/ma77jtk0f8758eah0fs4ghjq46/38939700150.pdfIn PDF document text
    • http://sad-azov.ru/wp-content/plugins/super-forms/uploads/php/files/81de0673491f56c435425da0d20173aa/79080694498.pdfIn PDF document text
    • http://ne-moloko.ee/wp-content/plugins/super-forms/uploads/php/files/b1f9b9c19fc2dc92d99244021fce9661/13221561338.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_off0000f02e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF02E 5280 bytes
SHA-256: a0f8c97bd37a68e4536edab593c9e6d031e10d2656aac170639207a3282c3a12
font_01_sfnt_off00010234.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10234 10840 bytes
SHA-256: 9d311c4022d851d78ea580dde7313e115d9ee4652bda736228cfa60be8b41baf