Malicious PDF — malware analysis report

Static analysis result for SHA-256 18f618e7328afbbb…

MALICIOUS

PDF

68.6 KB Created: 2021-06-24 10:51:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-04
MD5: 1df73b8ef0b451ca47ba45d5456fdfb7 SHA-1: 2e1bf272526e7ac6024339a294b03a9d291134fb SHA-256: 18f618e7328afbbbf333534741cb072fad18707d709c60588155ea9b41c6aa7c
96 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://highendschmiede.de/highendfiles/file/29794876010.pdf In PDF document text
    • http://driscollandgibson.com/images/edit_images/file/35969712820.pdfIn PDF document text
    • http://amphorabeautyclub.com/campannas/file/84013818893.pdfIn PDF document text
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ce2f6d44a54---28428867695.pdfIn PDF document text
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/119e61c5d2629bc115d052bf789a5962/4753400311.pdfIn PDF document text
    • http://lobanowscy.pl/userfiles/file/18847813005.pdfIn PDF document text
    • https://pacpartner.net/images_client//imagesfile/vonamu.pdfIn PDF document text
    • http://bugaboo-buffalo.eu/UserFiles/File/57615750260.pdfIn PDF document text
    • http://liga-stf.ru/i/upload/files/miduwuz.pdfIn PDF document text
    • https://xlux.vn/wp-content/plugins/super-forms/uploads/php/files/p7keacps2kqfaar5egc1aevvf4/53244657526.pdfIn PDF document text
    • https://funkydrop.shop/wp-content/plugins/super-forms/uploads/php/files/c5d99b1b55cb2cce1caa35648f2dbccb/guzefale.pdfIn PDF document text
    • http://elmiraclassiccountry.com/wp-content/plugins/super-forms/uploads/php/files/48varnm2moefd8pa9s6bk8djg5/70675165397.pdfIn PDF document text
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/4eec8391261074b1875b6d1e98deb943/donewenitu.pdfIn PDF document text
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076c3ab56ebc---katinudib.pdfIn PDF document text
    • http://paillasse.hu/userfiles/file/zixavokidagujufuw.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/BvfzZFkJO3s/uplcv?utm_term=pdf+add+numbersPDF 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_off0000d00e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD00E 5160 bytes
SHA-256: 3ef5d253bd781520580182c4f124dc1d2492a35466f125d5a6cf61a3f4ef7cf2
font_01_sfnt_off0000e180.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE180 10660 bytes
SHA-256: cfe846c88bdc0e2f870a65e046015439fda18d6e52faee840e60b832f133f26a