Malicious PDF — malware analysis report

Static analysis result for SHA-256 0692a23142a3133c…

MALICIOUS

PDF

84.3 KB Created: 2021-08-21 18:12:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 83f95a0bd735ff5e65cd7b0c432feba8 SHA-1: ab5954894ff596408ea229e1ce2f3100002bd495 SHA-256: 0692a23142a3133c05aa1d18e6daf6843cb6367e47d476d4fd0612f0d53a2dc1
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF document contains a large number of external links, many of which point to compromised CMS upload directories or disposable hosting. The ML classifier strongly indicates maliciousness. The document body is heavily obfuscated and appears to be a byproduct of the wkhtmltopdf tool, rather than user-readable content, suggesting its primary purpose is to host these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://synerhu.ru/uplcv?utm_term=tabla+de+conversiones+longitud+pdf PDF link annotation
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/8672c18e75377d5c388c40ee6e47def2/nokowino.pdfIn PDF document text
    • https://mebelpozakazu.ru/wp-content/plugins/super-forms/uploads/php/files/735dc048a920303bee86f5d7fd5ae106/gaxurikew.pdfIn PDF document text
    • https://kp-bs.ru/upload/files/wopekebodesunikadelufi.pdfIn PDF document text
    • http://edanieltour.com/FileData/ckfinder/files/20210614_75F9BF7BBA825886.pdfIn PDF document text
    • https://mgogs.com/mgfiles/file/54659471670.pdfIn PDF document text
    • https://bazk.info/public_htmluploads/file/matugirik.pdfIn PDF document text
    • http://lungtransplantopen.com/clients/d/de/de7cc03d42bda6b8b84c8ac9728529bb/File/17280859942.pdfIn PDF document text
    • http://nhuaduongnhapkhauaz.com/upload/files/vaputado.pdfIn PDF document text
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/boej38dd11so19fjnlvgsq3gp5/sotobewefoteralarodisu.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/edfa604eb0d84349aaa6fd2275a28b00/diguvo.pdfIn PDF document text
    • https://www.cylinder96.ru/admin/ckfinder/userfiles/files/pugajujit.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a59c6a5bb35---xadaxejo.pdfIn PDF document text
    • http://hayatteknoloji.com/webimage/file/59039958810.pdfIn PDF document text
    • https://martensmgt.com/business_school/uploads/file/zupekeg.pdfIn PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f05ff27adb---88560169288.pdfIn PDF document text
    • http://85560891.com/upfolder/e/files/20210731212239.pdfIn PDF document text
    • http://amon-syotengai.com/userfiles/file/zudinumapul.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608137c9a167d---8137326506.pdfIn PDF document text
    • https://digireg.pl/upload/zabagogibewavudonude.pdfIn PDF document text
    • http://contextuae.com/resimler/files/69675876669.pdfIn PDF document text
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088d5b19c52a---tatekigoboropidotunu.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ffff288fcc---pegameruwi.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_off0000e471.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE471 17308 bytes
SHA-256: 4c5d4d46491e2596b320984392d239ee89b8c84c1821bcf9a22483cdb3dc56d9
font_01_sfnt_off00011073.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11073 11064 bytes
SHA-256: ccf8827e442c04ebe87ca58367cb70bf7f2030ee578d584fb232c28202c25f50
font_02_sfnt_off000129f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129F7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1