Malicious PDF — malware analysis report

Static analysis result for SHA-256 fef6d0142a63f88c…

MALICIOUS

PDF

79.3 KB Created: 2021-09-20 15:47:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: e5609a7aa7c21d2cb62b04596052b62c SHA-1: ac23493b1fa0b453411380e7150433241eec71df SHA-256: fef6d0142a63f88c83cb57c8573dae4cea20363030140a3697dfab1ff554fc35
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 upload directories or are hosted on disposable domains, suggesting a link farm or redirection scheme. The ML classifier strongly indicated maliciousness, and the structure of the links, including UTM parameters, points towards SEO manipulation or traffic redirection for malicious purposes. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://chcial.ru/uplcv?utm_term=como+conectar+movil+android+a+mac PDF link annotation
    • http://nadiadsa.org/userfiles/file/zubutodixusupiliv.pdfIn PDF document text
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613eca70c9868---19487503348.pdfIn PDF document text
    • http://carrozzeriabosini.net/userfiles/files/33507584053.pdfIn PDF document text
    • http://olsztyntransportmedyczny.pl/userfiles/file/zaduwukilonu.pdfIn PDF document text
    • http://martom24.pl/martom/userfiles/file/54808713516.pdfIn PDF document text
    • http://adasbruiloften.nl/userfiles/file/jitemupimisigekepamanar.pdfIn PDF document text
    • http://sriagasthiyarastro.com/FCKeditor/userfiles/file/84155168783.pdfIn PDF document text
    • http://tecniagua.es/uploads/ckfinder/files/50525645672.pdfIn PDF document text
    • http://gabinetortodontyczny.eu/userfiles/file/pofewokevowusumuv.pdfIn PDF document text
    • https://art-gallery.mn/uploads/files/95971858353.pdfIn PDF document text
    • https://truckforceone.com/upload/editor/file/satafuvemawe.pdfIn PDF document text
    • http://daotaoyduoc.org/wp-content/plugins/super-forms/uploads/php/files/5c4ad2b11b275dcebf96a2b9c124b1f5/gabexulesik.pdfIn PDF document text
    • https://taipeitccia.org/CKEdit/upload/files/39904411254.pdfIn PDF document text
    • https://tabularasa.lv/sites/tabularasa/uploads/documents/files/pububurizome.pdfIn PDF document text
    • http://guss-ex.de/uploads/fck/file/60185032513.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614145eb3c64b---58199326219.pdfIn PDF document text
    • http://devison-matras.com/upload/file/74041279683.pdfIn PDF document text
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/161365e54c22b3---zufatunoforaloduxugamo.pdfIn PDF document text
    • https://futurefacesnyc.com/uploads/file/jekoxojitofogaji.pdfIn PDF document text
    • https://designmaster.in/scgtest/eec-new/codelibrary/ckeditor/ckfinder/userfiles/files/jaxoz.pdfIn PDF document text
    • http://yishiweb.com/upfiles/files/20210920_014858.pdfIn PDF document text
    • https://xyoaa.org/sites/default/files/files/17519504065.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_off0000d12f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD12F 10460 bytes
SHA-256: 3f9d7efac7339a3908562d9af7733ca26a2fd87613e667ccd697203182c10812
font_01_sfnt_off0000e8eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8EB 18180 bytes
SHA-256: 7f89aa31f88daaede7b8fceff9411fadf7ca99bceb27143a3c734c879816f720
font_02_sfnt_off0001174f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1174F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1