Malicious PDF — malware analysis report

Static analysis result for SHA-256 61a7dcebbe60c563…

MALICIOUS

PDF

71.6 KB Created: 2021-06-19 17:16:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: d88c6e939ad5b35a1c8768398bbecc02 SHA-1: e976250cee51370ca592c808a050f5f35f9c3941 SHA-256: 61a7dcebbe60c56355880c743e8e2c3ddb0f9b6be0aac01b329556a61666e8c5
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised CMS upload storage, suggesting it's used to distribute further malicious content or phishing pages. The embedded URLs, while some are marked benign, are part of a pattern to obscure the true destination and purpose of the document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084e6bad5658---88014781773.pdf In PDF document text
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1608298193af6e---fumilefogex.pdfIn PDF document text
    • http://rana-international.com/userfiles/files/bekitisosunetujabo.pdfIn PDF document text
    • http://meble-tk.pl/userfiles/file/17725782413.pdfIn PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/160759332865c4---59785347887.pdfIn PDF document text
    • http://acetuitioncentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b402bae337e---52700047410.pdfIn PDF document text
    • http://ecohort.com/userfiles/files/wosowuwiwaseralefez.pdfIn PDF document text
    • https://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/6f20f1f30d8460223010594b6032e22e/2788487985.pdfIn PDF document text
    • https://ocvirapuato.com.mx/wp-content/plugins/super-forms/uploads/php/files/80c493edd3aaab423931088080486e1f/67158342342.pdfIn PDF document text
    • https://www.isgs.org/wp-content/plugins/super-forms/uploads/php/files/87fd00e42fb5bc4861c1596d8d94533a/46838287818.pdfIn PDF document text
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/d7358825a3d0072480475499a64e8cc2/7475655557.pdfIn PDF document text
    • https://dienlanhbachkhoa.info/upload/files/zawusefuk.pdfIn PDF document text
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bcdb68bb144---86408074129.pdfIn PDF document text
    • http://n2nlah.org/UserFiles/file/6509113856.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/FevRqgeaUVY/uplcv?utm_term=apex+legend+new+legendPDF 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_off0000dade.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDADE 4792 bytes
SHA-256: 3c8fead80066a8b5cabc730f6a435ab8dcf8436b51d8bfd3a12cdac0cab9d181
font_01_sfnt_off0000eb5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB5A 11328 bytes
SHA-256: 147f66148aafe11feb41a07cb22056d1fb4e4a782e123ceb0e9c9ab3084ab7ea