Malicious PDF — malware analysis report

Static analysis result for SHA-256 936bca23d18a0a84…

MALICIOUS

PDF

71.5 KB Created: 2021-05-07 08:19:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: 8424b291389d88278c26f5bd5ebb1d0e SHA-1: 770a8dda6a8ed0a4e7531e2f275ae268fe48764c SHA-256: 936bca23d18a0a845565fe0d2a880dee3eab7d0ef8a8da39ef194fca96bfc101
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 https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608c904e740e6---suremit.pdf In PDF document text
    • http://all-pass.com/folder/editor/file/40813386112.pdfIn PDF document text
    • http://www.farparts.cl/wp-content/plugins/formcraft/file-upload/server/content/files/1606cd692c28e5---47289237496.pdfIn PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160804ef2bc5b9---67155319938.pdfIn PDF document text
    • https://alphacleanwashing.com/wp-content/plugins/super-forms/uploads/php/files/dcdc3e5fb4524c1850098669685443bf/fijifeseb.pdfIn PDF document text
    • https://ccveg.org/wp-content/plugins/super-forms/uploads/php/files/jb9pnd45qsgcqht3grlef78rp6/54084195330.pdfIn PDF document text
    • http://webscape.co.bw/wp-content/plugins/formcraft/file-upload/server/content/files/160897f7add225---jaberodiba.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9608ad4c1---51589197384.pdfIn PDF document text
    • http://akcjonariusz.com/UserFiles/file/87109485456.pdfIn PDF document text
    • https://vickers-electronics.co.uk/wp-content/plugins/super-forms/uploads/php/files/b236db2b27f8d0040066ee6f395e86e7/guzekatiku.pdfIn PDF document text
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073cc6d2ea3f---13513381247.pdfIn PDF document text
    • https://janeunchained.com/wp-content/plugins/super-forms/uploads/php/files/fa6t27f8hru9jg76bdfaocv4mq/68778577464.pdfIn PDF document text
    • http://bazatalty.pl/wp-content/plugins/super-forms/uploads/php/files/7972be4036c8b478e3a059b201ef2557/bixidowe.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1607cd0af1fc11---16015509868.pdfIn PDF document text
    • https://advance-pack.com/editor_upload/file/81309418754.pdfIn PDF document text
    • https://liniagdanskzydowo.pl/files/13642847942.pdfIn PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/afk4c5c3pbph68t608n7ket5q4/54104468528.pdfIn PDF document text
    • https://trichynext.com/wp-content/plugins/super-forms/uploads/php/files/be062ede542b25df02a71dca99061913/suzirifazebabejojoxaka.pdfIn PDF document text
    • https://akarchlight.com/wp-content/plugins/super-forms/uploads/php/files/fe192e69d339e7fe552a032c95098af3/35574197084.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8408a996f---fobijowifidoxutopu.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/LPIa9PGmDLg/uplcv?utm_term=bluetooth+speaker+volume+booster+apkPDF 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_off0000da62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA62 5372 bytes
SHA-256: 69309617d990c446ce0120fb5f63bc2e7c4d9757f4134d2b3eaf3ed9be101650
font_01_sfnt_off0000ec7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC7A 10520 bytes
SHA-256: 17a1cca80068023a89042a6d442861e129d9c36fd2674ad9304e4a170d80c070