Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b7639f1e2552c3c…

MALICIOUS

PDF

101.1 KB Created: 2021-05-06 21:04:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-02
MD5: fd3aa7ec5d5c974b258b7f1cf26ce23c SHA-1: cf341821d4030ed0a636c2e5781c35b10e13a697 SHA-256: 4b7639f1e2552c3ca6252d112581573095a4080f3d5e5970eb2af149368733ee
156 Risk Score

Malware Insights

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

The PDF file contains numerous links, many of which point to compromised WordPress sites acting as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The presence of multiple external URIs and link farms suggests an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.corridar.com/wp-content/plugins/super-forms/uploads/php/files/okm9s3lp5eo1sj9skru6l8rr0b/63968123832.pdf In PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084b7dfc1fb1---gotif.pdfIn PDF document text
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088b5e5048ca---28562534295.pdfIn PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608e956cc7bc0---95766975940.pdfIn PDF document text
    • http://entone.es/wp-content/plugins/super-forms/uploads/php/files/4609944db42ab2cd496d6decd64a1051/4500485090.pdfIn PDF document text
    • http://www.belladermeestetica.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606fa32ce530b---bosepuvujetage.pdfIn PDF document text
    • http://miamiwars.pl/wp-content/plugins/super-forms/uploads/php/files/655782b7218efb6479b246f544a8cd67/gatefabuputofub.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/1608150a8b5025---21044104763.pdfIn PDF document text
    • https://wecafephuket.com/wp-content/plugins/super-forms/uploads/php/files/h2m5h5r8592vmmi14aq4no0haq/6395661005.pdfIn PDF document text
    • https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076d18102385---48262662647.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/c2aro9itjpabm4l46a1q60oiq2/kutesezofunitararaf.pdfIn PDF document text
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076041c09d47---43020359913.pdfIn PDF document text
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160801608242fc---pubijituv.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1606f425f0a43d---34227130641.pdfIn PDF document text
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/1d5da86177a65540a62458c0ee6e5689/75806446243.pdfIn PDF document text
    • https://bangprice.combangprice.com/beta/cms_image/file/jivaxukuked.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/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=contexto+social+de+la+profesion+pdf+uanlPDF 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_off00014a73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14A73 5124 bytes
SHA-256: a01760b54af3da344f8cb4ec0a21c7ff8dc0f1a3cf7fafc89e4147f563a338ce
font_01_sfnt_off00015bef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15BEF 13940 bytes
SHA-256: a71e625b135edff69f689024dc97022e0023cb38127d0ab8971ddd2900287115