Malicious PDF — malware analysis report

Static analysis result for SHA-256 55385bb66e49f502…

MALICIOUS

PDF

82.0 KB Created: 2021-09-11 08:48:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 58ae59f4d9297a17be493eb01cb94c6b SHA-1: 7f211efd02550d60fc3d00a683cc26283d407b89 SHA-256: 55385bb66e49f50219f60c737cfa4f97fdc9196c00587d3e57dbbc1ed0186f0f
164 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code or redirecting users. Several heuristics indicate the PDF acts as a link farm, pointing to compromised WordPress upload storage and disposable hosting, suggesting an attempt to distribute malicious files or redirect to phishing pages. The ClamAV detection and ML classifier strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://too.kg/wp-content/plugins/super-forms/uploads/php/files/6002368358cae7d98b721abd6353a281/vusofexu.pdf In PDF document text
    • https://sensormaticltd.com/app/templates/js/ckfinder/userfiles/files/77333308842.pdfIn PDF document text
    • http://grandioso.asia/editor_upload_image/file/34484536723.pdfIn PDF document text
    • http://worthingtonpark101.com/userimages/33069277422.pdfIn PDF document text
    • https://airflow-skateboards.com/upload/file/riritavofirorozijewepe.pdfIn PDF document text
    • http://studioguagnoni.it/userfiles/files/21180241584.pdfIn PDF document text
    • http://wxeina.com/userfiles/files/48778796353.pdfIn PDF document text
    • https://mountainbrookbuilders.com/home/mountain/public_html/ckfinder/userfiles/files/sitipipurapafevelusuk.pdfIn PDF document text
    • http://xenangheli.vn/public/files/28645859215.pdfIn PDF document text
    • http://sspvjd.com/FileData/ckfinder/files/20210905_3D3E00F9C3C7864B.pdfIn PDF document text
    • http://tcihk.com/userfiles/65194685246.pdfIn PDF document text
    • http://teewer.mn/ckfinder/userfiles/files/kurasumefepefajo.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/d8fpv9qsq238v28tge96bcoke3/zulupawavonivumu.pdfIn PDF document text
    • https://www.moxiclear.com.au/application/third_party/ckfinder/userfiles/files/zakawi.pdfIn PDF document text
    • http://yoga-privates.com/yoga-privates/file/dosebim.pdfIn PDF document text
    • http://comicpapyrus.com/wp-content/plugins/super-forms/uploads/php/files/5c7d786c920d106c55d48406ca0ea39c/63164369284.pdfIn PDF document text
    • http://nwhouse.ru/uploads/file/74396576744.pdfIn PDF document text
    • http://sakuragiramenandsushi.com/uploads/files/jirozapunapejanifati.pdfIn PDF document text
    • http://uticachemical.com/files/upload/files/34711531228.pdfIn PDF document text
    • https://korzayithalat.com/spot/admin/fckeditor/userfiles/file/sudexogikumubazikimem.pdfIn PDF document text
    • https://madhubanindiancuisine.com/nbloom/fckuploads/file/dirawaxunukubekupifidud.pdfIn PDF document text
    • http://xutricolor.com/uploadfile/files/46135430133.pdfIn PDF document text
    • http://parfumerieindex.nl/images/uploads/22051957216.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/fojowavefurimitem.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=gostream+official+websitePDF 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://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_off0000dbbc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBBC 17744 bytes
SHA-256: a885a9b2289efb92085aa9ec1f8e6c703ad9a48b158afafeafdb6805204737e9
font_01_sfnt_off000109bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109BD 10660 bytes
SHA-256: 151db924113082954b6ca4cb43d3ad1429ea4f5f916c8ae6f16e45e966efb5cc
font_02_sfnt_off00012253.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12253 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1