Malicious PDF — malware analysis report

Static analysis result for SHA-256 213fa5dde2aba2fa…

MALICIOUS

PDF

83.9 KB Created: 2021-09-16 18:10:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: e466632fde405948c75d079e36dad2ac SHA-1: 38c3b1d9d9e2e8e898914c27bb55db6d23ad1b31 SHA-256: 213fa5dde2aba2fad94a118d93f20c91dd2ac6caf238f9cca852f9eac6986221
96 Risk Score

Malware Insights

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

The PDF file contains a link farm with numerous URLs pointing to various domains, many of which are associated with compromised CMS uploads or disposable hosting. The ML classifier strongly flagged this PDF as malicious, and the heuristic firings indicate it's designed to host external links. The primary purpose appears to be redirecting users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://bcbc3399.com/upload/files/25191010277.pdf In PDF document text
    • https://yesilkoyluleriz.biz/resimler/files/81819194743.pdfIn PDF document text
    • https://ashasuchikala.com/ckfinder/userfiles/files/sozaxodokujuzilitobifibu.pdfIn PDF document text
    • http://hglobaltour.com/FileData/ckfinder/files/20210909_18B42F271EBC6896.pdfIn PDF document text
    • https://creationstationdance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ff9094cc43---93183453664.pdfIn PDF document text
    • https://spherule.org/wp-content/plugins/super-forms/uploads/php/files/35tnb1plk56938n52s7tsco1e0/mezozumusaxupizisabezuba.pdfIn PDF document text
    • http://keemunblacktea.cn/uploads/file/130710478246.pdfIn PDF document text
    • http://studiocommercialedelpiano.it/userfiles/files/34073975920.pdfIn PDF document text
    • http://ar-intl.net/wp-content/plugins/super-forms/uploads/php/files/8a281eonaqd3qbc8t8rus0bnu7/63050589945.pdfIn PDF document text
    • http://pro-roubenky.cz/UserFiles/File/pakawuxutikokikavuvok.pdfIn PDF document text
    • http://valencia.thepokeluau.com/uploads/files/bekusefunewuwazemedam.pdfIn PDF document text
    • https://sindicav.com.br/ckeditor/ckfinder/userfiles/files/84366105735.pdfIn PDF document text
    • http://stjconsulting.it/userfiles/files/36040044462.pdfIn PDF document text
    • http://secureyun.cn/uploadfile/file///2021091615161842.pdfIn PDF document text
    • http://internationalnetworksolutions.net/files/In PDF document text
    • http://warwick-ems.org/userfiles/file/14040011140.pdfIn PDF document text
    • http://j1ent.com/userfiles/file/20210916055904.pdfIn PDF document text
    • https://jazykovytabor.topenglish.sk/app/webroot/gallery/files/35153891228.pdfIn PDF document text
    • http://tk-weld.com/images/library/File/76094152651.pdfIn PDF document text
    • https://laflammerouge.ch/userfiles/files/duvibifi.pdfIn PDF document text
    • https://bhsbeacon.com/FCKeditor/file/54663934918.pdfIn PDF document text
    • https://inchirieriavioane.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613de7f608a0d---29906230461.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=in+internetwork+network+layer+is+responsible+forPDF 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_off0000e50c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE50C 10736 bytes
SHA-256: 7f6dd0616ea4b427c936a009d6b2c9c06ff519f431a8342e10e36206c8043449
font_01_sfnt_off0000fdb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDB3 17016 bytes
SHA-256: 0d67c4818348eebfb80d12e8868ec8d89f23216f1bdebf93d3d0f2fe2eaeaccd
font_02_sfnt_off000129ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129AC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1