Malicious PDF — malware analysis report

Static analysis result for SHA-256 51740e2e5bf0a31b…

MALICIOUS

PDF

70.0 KB Created: 2021-06-21 01:20:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: cb033b800271aae2d6379e237c941297 SHA-1: 76dd1c94a5cbaf44fd12ba5fe5e201bd3c0d9829 SHA-256: 51740e2e5bf0a31b0ee2f9e94804031ed7b8116cf4b5fefd438c43c838e34b7f
144 Risk Score

Malware Insights

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

This PDF was flagged by an ML classifier as malicious. It contains a link farm pointing to compromised WordPress upload storage and other disposable hosting, suggesting it's part of a distribution network. The presence of a 'password-protected archive handoff' heuristic indicates the document likely instructs the user to open a password-protected archive, a common tactic to evade gateway security scanning.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://broadviewlibrary.org/uploaded_bvlib/file/7674870128.pdf In PDF document text
    • http://vogiantinhmach.com/media/ftp/file/sijagetibesizukem.pdfIn PDF document text
    • http://bright-mineral.com/uploadfile/file/2021052518224525.pdfIn PDF document text
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/3de6c88be2a32ff9958f001450e8c375/84579562574.pdfIn PDF document text
    • https://elnativocoffee.com/silver/upload/files/16024760974.pdfIn PDF document text
    • https://www.parkgest.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16087ff5a9f220---joture.pdfIn PDF document text
    • https://www.alignerco.ca/wp-content/plugins/super-forms/uploads/php/files/751e87ada255f9dd87206da4d3986781/69480944759.pdfIn PDF document text
    • http://hanhthien.net/uploads/file/63613234575.pdfIn PDF document text
    • http://middlegeorgiacoinclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608768f78434f---3602445953.pdfIn PDF document text
    • http://microcement.ua/userfiles/file/xavedolulebimavimu.pdfIn PDF document text
    • https://expeditions-travel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070023c77a83---1103146623.pdfIn PDF document text
    • http://www.tenniscanberra.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16071f4afdf6f0---wubodegiru.pdfIn PDF document text
    • https://israelonthehouse.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bcad3e6ef3b---tatojepisonazegewor.pdfIn PDF document text
    • https://iwnta.com/userfiles/file/12925593279.pdfIn PDF document text
    • https://fnb-concepts.com/images/uploads/files/66114646611.pdfIn PDF document text
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/16077581b29e3a---lilox.pdfIn PDF document text
    • http://host.keraladreamhomes.com/~viswabrahmathach/admin/fckeditor/editor/filemanager/connectors/php/userfiles/file/matofozomavo.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/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=download+gta+adrenoPDF 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_off0000d459.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD459 4908 bytes
SHA-256: 198ec6ecc76b166e66dd31677fad379dc780d727267449c011383f2e6315e364
font_01_sfnt_off0000e531.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE531 11240 bytes
SHA-256: 123a3e947f3c3fed39ec05cdfdeab4748fe02e8bcedf980da016862fa8cf9623