Malicious PDF — malware analysis report

Static analysis result for SHA-256 11acd4455f2fd315…

MALICIOUS

PDF

74.6 KB Created: 2021-09-06 15:08:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 7b3828eacb7bed0f845e627cbe503aa3 SHA-1: 0c6a3c0d903fde22d11801f573fe18abd50bdd22 SHA-256: 11acd4455f2fd315b2d74d448ae99632dd2641ad090dc3bd2183233cc35fcd24
96 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed for SEO manipulation or to distribute further malicious content. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent. No scripts were extracted, and the document body was unreadable, but the URL structure and heuristic firings are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • 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://crysiq.ru/uplcv?utm_term=cyrillus+kreek+onnis+on+inimene+pdf PDF link annotation
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160bc1c3db95e4---90428661847.pdfIn PDF document text
    • https://novahealthclinic.ca/userfiles/file/rokutibinomufelizex.pdfIn PDF document text
    • https://migger.dk/userimages/file/jozunu.pdfIn PDF document text
    • http://urgentcarepb.net/userfiles/file/42027445037.pdfIn PDF document text
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/d91faa384848df941a3e41fafdb0fdc4/78199298489.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b49149de308---lofidesadorimu.pdfIn PDF document text
    • http://hoteldanang.vn/uploads/images/files/4502809799.pdfIn PDF document text
    • http://gcsiva.com/files/userfiles/file/93883673880.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad211a735b9---manufilufamebo.pdfIn PDF document text
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/2m5e89cte100pp05r2uc5fu502/73736326094.pdfIn PDF document text
    • https://www.kiakaha.gr/wp-content/plugins/super-forms/uploads/php/files/7i159lk1olkr8qbphvftel8ijt/letoritogivigem.pdfIn PDF document text
    • http://beetsom.com/PROGRAM_FCKeditor_UserFiles/file/7659078576094bc0603b67.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dc83ba260bb---32975196166.pdfIn PDF document text
    • https://drddvichitra.com/userfiles/file/lopotuve.pdfIn PDF document text
    • http://sozopolihills.com/userfiles/file/61260187639.pdfIn PDF document text
    • http://vegman-kzn.com/ckfinder/userfiles/files/56495357018.pdfIn PDF document text
    • http://indyskischool.com/ckfinder/userfiles/files/40177995835.pdfIn PDF document text
    • https://urbanshapes.in/userfiles/file/xewotesupegemuketole.pdfIn PDF document text
    • https://skinrepublic.vn/webroot/img/files/xekonitasovapenozet.pdfIn PDF document text
    • http://andrelandberg.com/userfiles/file/87488937008.pdfIn PDF document text
    • https://consultemergingmarkets.cubsindia.com/files/fawilo.pdfIn PDF document text
    • https://ahreco.com/uploads/news_file/13442560634.pdfIn PDF document text
    • http://abwmountvernon.com/uploads/files/dukitogalazepoxexis.pdfIn PDF document text
    • https://globalclassic.org/wp-content/plugins/super-forms/uploads/php/files/b18ap2atn6e4ov1tht2ek2d8t0/pudevolew.pdfIn 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bc6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC6B 10736 bytes
SHA-256: e5fc09f3d637c1bb271b3ae7476395488fcc88c87658e5fa486d286301306c43
font_01_sfnt_off0000d512.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD512 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ed24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED24 18064 bytes
SHA-256: 8d1293a573f3e6020fa375b058b91b7bae8be2c4f05d50a0e82dbfcab6b10a1c