Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb41f3b690249134…

MALICIOUS

PDF

79.3 KB Created: 2021-04-10 17:22:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-10
MD5: d0e923cd2cb823f66e9a5d3081b5d17a SHA-1: f23ec38a328ec10d33fd41cf652e31a50b41a5d1 SHA-256: fb41f3b690249134deb49f614cc92b825296b1ef14c0bd2ca16d94340824334f
186 Risk Score

Malware Insights

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

The PDF file contains a significant number of external links, as indicated by the PDF_SEO_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM heuristics. These links point to various domains, including suspicious ones like nipisod.ru and 4338bacchus.com, suggesting a link farm or phishing attempt. The ML classifier and ClamAV detection further support the malicious nature of the file, classifying it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://nipisod.ru/strik?utm_term=how+much+does+a+covid+test+cost+in+canada PDF link annotation
    • http://4338bacchus.com/how_to_charge_a_g_shock_solar_watchiuonf.pdfIn PDF document text
    • http://astrology-personal.online/42876361172kybjf.pdfIn PDF document text
    • http://return-0.com/beverivonajetoparixugogooshq9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369328/normal_60106c82002d6.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4392877/normal_5ff3ecb261ed0.pdfIn PDF document text
    • http://hookup671.site/rataxonukuix56d.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/4057b134-d0b1-47dc-a2ed-ea3730199397/34007083610.pdfIn PDF document text
    • https://a181bb3e-7445-4f1f-a1cf-b2fe66c13e92.filesusr.com/ugd/91ce54_b1276a86694747699f89af4e7446a687.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/990ce472-2a47-41dc-b626-5ac2b3533d34/what_does_maintenance_required_light_mean_on_lexus.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0b27000b-0e3d-4e71-9b87-304ceaaccafc/exilim_casio_camera_price.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8bc3eba4-242d-4178-9a77-1512bb43837f/grade_11_college_biology_textbook_online.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/946b7668-883e-4dcd-a3dd-412de374d794/night_owl_security_camera_extension_cable.pdfIn PDF document text
    • https://2e21b658-2967-4279-8f18-a03590b678a5.filesusr.com/ugd/f5e1b2_073f0368225941079aa519d1939baf75.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/f68fb53f-0ee7-4a67-8d0a-eb3df2ce929d/jeranemip.pdfIn PDF document text
    • https://a3720f92-bdaa-4449-a3ff-14f36884d2d5.filesusr.com/ugd/afadc3_e3204fb55da04e8b92b6c1cb0e89a31d.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/36820d27-5907-4625-85b3-7e3b1735e57a/faiths_of_the_forgotten_realms.pdfIn PDF document text
    • https://cb0920a4-0dfc-4587-8161-bd3bf883b043.filesusr.com/ugd/df391a_4856db497530496694b6a617e9d64ca0.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/54832ed0-9d67-4ad4-8725-74ee590bad03/29893166296.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3a9516f9-d128-4c33-b1da-3d35e55547f4/debekumotafisuzagidulatar.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/660b414d-12cf-4475-b571-6dd38ea840e1/23458521129.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_off0000f892.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF892 5164 bytes
SHA-256: 7944cf4cced543628a24130d1a9d25088f74ef5c98332c966cec1ac23a3ff638
font_01_sfnt_off00010a12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A12 11208 bytes
SHA-256: 09b48182f1e0c5a77a2a5b5919b626abc254f04ee3f93cfc17ca4e9c5e5a1c71