Malicious PDF — malware analysis report

Static analysis result for SHA-256 a24981354f22088b…

MALICIOUS

PDF

74.7 KB Created: 2021-03-21 01:05:55 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 90287ef1aabec58be251cf796efc55bb SHA-1: ec94bb7849c8c327305b7f44f1775050e2220071 SHA-256: a24981354f22088b9aa6701ff4dbc24f286cd875267e3e9616783ef379f38c27
126 Risk Score

Malware Insights

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

The PDF contains a large number of external links, identified by the PDF_SEO_LINK_FARM heuristic, pointing to various domains. One of the primary links directs to 'https://gimoguvi.ru/award?keyword=parliamentary+system+of+uk+pdf'. The ML classifier strongly flagged this PDF as malicious. The presence of a link farm on disposable hosting suggests an attempt to manipulate search engine results or distribute potentially malicious content via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://gimoguvi.ru/award?keyword=parliamentary+system+of+uk+pdf PDF link annotation
    • http://xumupizaxuto.scienceontheweb.net/og_mandino_the_greatest_salesman_in_the_world_summary.pdfIn PDF document text
    • http://lusaxesa.iblogger.org/18570027143.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4499283/normal_6020b372e3d0d.pdfIn PDF document text
    • https://komamezumef.weebly.com/uploads/1/3/1/3/131398541/e9a028.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4408851/normal_5fd7ca62e34c8.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4491686/normal_600530a959004.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490265/normal_6023857b06090.pdfIn PDF document text
    • https://wibipujesotut.weebly.com/uploads/1/3/1/3/131398272/7093361.pdfIn PDF document text
    • https://tigatomexinopi.weebly.com/uploads/1/3/4/4/134460375/5427777.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4483338/normal_600e5d74a2f44.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375342/normal_603fd71e26c28.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4447095/normal_5fe7a0b67f477.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4491686/normal_5ffeaac266a11.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4407996/normal_5fd125b86f212.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/cd2e2db1-b731-411a-9916-f32e0d4baea9/60481193824.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d85771b3-8632-4c82-973f-8db78a7ff547/4_pics_1_word_level_262.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/23829232-57ff-48ed-ad2d-24f1daace2ad/11911378297.pdfIn PDF document text
    • http://nesemuvalumut.rf.gd/fipoduditekunub.pdfIn PDF document text
    • http://lujubozugib.epizy.com/plt_legend_bluetooth_peripheral_device_driver.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2f0c5179-141a-4d9c-b732-1754c8637eba/22152824735.pdfIn PDF document text
    • http://vupaguriwedizid.atwebpages.com/95560723789.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e738.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE738 5356 bytes
SHA-256: d77fb785c478c1aecb1bfaf56907b96dc6168bdacea1ff6cb20f5b082f4a7391
font_01_sfnt_off0000f963.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF963 10508 bytes
SHA-256: 500dfd22f752c8255324e0df83017d78d5a2a23e98c4250b5f69b7bbb99ac077