Malicious PDF — malware analysis report

Static analysis result for SHA-256 66988921c06b0cec…

MALICIOUS

PDF

74.4 KB Created: 2021-04-29 04:57:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: 7283542421a1761c973c08545d83a9a9 SHA-1: 4c7ca46fb4c1b9b8d940269ad7829e53a5cdda8c SHA-256: 66988921c06b0cece23587994dd99b92fce9abfdc17aabf2997c93914025ddeb
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised WordPress sites, identified by heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM'. The ML classifier and ClamAV detection strongly indicate malicious intent. The embedded URLs suggest the primary purpose is to redirect users to potentially malicious content hosted on these compromised sites.

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 http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a6622a3009---15016854507.pdf In PDF document text
    • https://thewaves.net/wp-content/plugins/super-forms/uploads/php/files/9ecckvba8l9r3ij7f5jq7bc2tt/24866182651.pdfIn PDF document text
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074a8fe2d3bc---remanowiligixedoki.pdfIn PDF document text
    • https://completecollegestrategies.com/wp-content/plugins/super-forms/uploads/php/files/d5a66eb665bd901a4be35ec35da3b627/96445112398.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/1607d7c77433f2---fojotawelawudi.pdfIn PDF document text
    • https://beaufortbond.com/wp-content/plugins/super-forms/uploads/php/files/fd8ef7fb53a0f880c067cfaa3fb066f3/57536567525.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e2ae414901---44922089977.pdfIn PDF document text
    • https://georgiamusicpartners.org/wp-content/plugins/super-forms/uploads/php/files/f73fe6d212975fca9b3d73466632b279/kibiwitemugos.pdfIn PDF document text
    • http://workprohealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608519805c74b---nituri.pdfIn PDF document text
    • https://www.makathastaliklari.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606f59e984b1c---bijenomukiwo.pdfIn PDF document text
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607957a807146---sijevidizobudulesinex.pdfIn PDF document text
    • https://spherule.org/wp-content/plugins/super-forms/uploads/php/files/2645a079a8417354b7421fde98f7dbbc/giletu.pdfIn PDF document text
    • https://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/i1h4ln5dtrco07ov97hfk8eaio/jefatusiposo.pdfIn PDF document text
    • https://bayardplaza.co.uk/wp-content/plugins/super-forms/uploads/php/files/426442an7ho0d99ha71nfdpbto/kifowanexoniwamakasifegeb.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=asco+her2+guidelines+2018PDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e1b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1B7 5500 bytes
SHA-256: bb4db438fc4b42ea62230e443659f4d9b6c51cb6e4af3d67766117497d49cc15
font_01_sfnt_off0000f471.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF471 11244 bytes
SHA-256: 7f6f1a57a74f9de32ddc214dd42030778c8acd219d9059f8b993d5cb0db82baa