Malicious PDF — malware analysis report

Static analysis result for SHA-256 5987fb2cee4f8708…

MALICIOUS

PDF

91.6 KB Created: 2021-05-02 22:45:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 89d73f18b80bb616201be1cd2be8664d SHA-1: 0f5146ec141a22f225e2f7caef8e7ffdf3a7e02a SHA-256: 5987fb2cee4f8708a0e8a87eff5734891fb4a7a4b06052ec79d2c2277785accf
156 Risk Score

Malware Insights

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

The PDF file is identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to multiple compromised CMS uploads and disposable hosting sites, disguised as a 'combining like terms practice puzzle answers'. The presence of embedded URLs and the nature of the heuristics suggest it is designed to lead users to phishing or malware distribution 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 https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/ddfg4lpqo0g3ineh038tpf1hrt/vipatixijumumefewejava.pdf In PDF document text
    • http://gtshotel.it/images/file/19455706727.pdfIn PDF document text
    • https://www.keystonecare.co.uk/wp-content/plugins/super-forms/uploads/php/files/87cf9ca897033630427c052e2c38aaea/tebudexezer.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160892e9e68ce0---27036700880.pdfIn PDF document text
    • http://doubletroubels.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607632de2e7df---pekupuf.pdfIn PDF document text
    • http://jointrilogy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160870eafec6ac---basofifabomedobega.pdfIn PDF document text
    • https://tamtam.com.ua/wp-content/plugins/super-forms/uploads/php/files/a8ae8e5392b9cfeae2ba9ed47d971f85/88308815199.pdfIn PDF document text
    • https://polinagerz.ru/wp-content/plugins/super-forms/uploads/php/files/flnfhvmrodd88trcln07ovd4s2/98790283947.pdfIn PDF document text
    • https://www.dartmusicfestival.co.uk/wp-content/plugins/super-forms/uploads/php/files/6d4d47ad378e3bf01939323c1e50907e/79864279645.pdfIn PDF document text
    • http://www.segurosfacility.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607771264b3db---28719656742.pdfIn PDF document text
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/160708481e65bf---gerakezebixitotex.pdfIn PDF document text
    • https://dmvassociates.com/wp-content/plugins/super-forms/uploads/php/files/ca22bc7276dd5583afe666f1b91e1fc3/31400936441.pdfIn PDF document text
    • https://ecoinkworld.com/wp-content/plugins/super-forms/uploads/php/files/d1a59c1198d8fb83ff718139a23b632b/25637327517.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/3galds8ub5h50ot2nnrblr98p5/51841137542.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606cdfcce2c61---79475462686.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/GLLx1DTH0VQ/uplcv?utm_term=combining+like+terms+practice+puzzle+answersPDF 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_off00012660.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12660 5504 bytes
SHA-256: 1324f2ec99841c54e2c2c6c9768c3495d872b8c6d47c17246666c2ee540c065f
font_01_sfnt_off00013922.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13922 11648 bytes
SHA-256: d4d2c23a55bde73edb27acbc56a6d2183a5ee9cd024e949a6b3da685cdf5891b