Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9c6533572fb312a…

MALICIOUS

PDF

85.1 KB Created: 2021-06-16 20:12:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: 8199ba78fdf2367bbc8963766ace0da7 SHA-1: c0e9b82e7e87f0798dfce7d23e61e3b6afe0ba37 SHA-256: b9c6533572fb312a4588987291174e1811d690a7835dc4535cdde9abf78978f0
144 Risk Score

Malware Insights

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

The PDF document contains multiple links to external websites, many of which appear to be compromised CMS upload directories. The document also uses a lure related to a 'free download' and includes a visual download button, suggesting an attempt to trick the user into downloading a payload. The ML classifier strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 7

  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://infrive.ru/uplcv?utm_term=oxford+bookworms+stage+2+free+download PDF link annotation
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608386378c3b8---84488072257.pdfIn PDF document text
    • http://myxroad.com/upload/userfiles/file/%5C/vipelibetetazusafaf.pdfIn PDF document text
    • https://a2designbg.com/userfiles/file/29748333385.pdfIn PDF document text
    • http://www.zulfugar.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609415c9db9c9---92173868911.pdfIn PDF document text
    • http://ackerviewguesthouse.com/userfiles/file/39222913351.pdfIn PDF document text
    • http://bmsorganica.com/userfiles/file/72263256101.pdfIn PDF document text
    • https://krimgranit.ru/wp-content/plugins/super-forms/uploads/php/files/ffebe69b59b482507135008cdde848ab/10120797861.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160805edee89b4---56163553748.pdfIn PDF document text
    • https://dixietemporarystorage.com/wp-content/plugins/super-forms/uploads/php/files/f170e92204ca19267dfb6e32d29f501b/71313217099.pdfIn PDF document text
    • https://marksiegeldds.com/wp-content/plugins/super-forms/uploads/php/files/b0cddf4c0c430e44614d486b225aa04d/35584166824.pdfIn PDF document text
    • https://vinisfarm.com/wp-content/plugins/super-forms/uploads/php/files/077d8b71da6024832af0e2bed9961af0/1352667265.pdfIn PDF document text
    • https://www.idromeccanicasrl.com/idromeccanicasrl.com/wp-content/plugins/super-forms/uploads/php/files/7025bc4faa77ce974a26d293154cf008/23135621984.pdfIn PDF document text
    • http://jarauwerdaenzn.nl/userfiles/file/funajekowijopixujiximudi.pdfIn PDF document text
    • http://globaltruthmediagroup.com/clients/a/aa/aa8380eac451876ae6ab993bf3a720d6/File/patifafakaje.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_off000100c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100C4 5748 bytes
SHA-256: 1a0aaecfca20b4b0f696508bb3f752378f8d3e179c9f46416eddf352612dcc50
font_01_sfnt_off0001145b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1145B 21524 bytes
SHA-256: 60ff2441a9ca6dd10be23b57cf35216676a201b2329dd9a51488c2fbb963faaa