Malicious PDF — malware analysis report

Static analysis result for SHA-256 e541d54890a34c50…

MALICIOUS

PDF

85.4 KB Created: 2021-04-16 10:16:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-25
MD5: bf3d914ed3c244504069084066d38e96 SHA-1: f3236898e7a739ffa925d08d9d8afa2e97111dbb SHA-256: e541d54890a34c508799401294fb3e716e814b195b7ccc293d891303b1f6c49b
166 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • Image-heavy PDF with invisible link to suspicious domain high PDF_SUSPICIOUS_LINK_LURE
    PDF is a small image-heavy lure with invisible link annotations that send the user to a suspicious high-risk-domain URI. This matches credential-phishing carriers where the visible document is only a prompt and the real collection flow happens on the linked website.
  • 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://crophysi.ru/strik?utm_term=tablas+de+amortizacion+ejemplos+matematicas+financieras PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4454179/normal_6047b87121cf3.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4467573/normal_5fcc9e941dce5.pdfIn PDF document text
    • http://uplrezina.site/tisaropcfdzk.pdfIn PDF document text
    • http://ig-supportcenter.xyz/762132287791ybq6.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4381973/normal_5ff92f3b1e8ce.pdfIn PDF document text
    • http://starconflict-game.ru/86448071646nhex2.pdfIn PDF document text
    • http://korecos.ru/un_demographic_report_2019_male_femaleu6f9d.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4502493/normal_600369f570431.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4446774/normal_605026b8c1a76.pdfIn PDF document text
    • http://probmake12.xyz/warhammer_40k_3rd_edition_rulebookrqywy.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://63995da9-74be-4895-8497-a4fa53c9845d.filesusr.com/ugd/788c84_6599f95b716548a3b74fc3047c39a645.pdf?index=trueIn PDF document text
    • https://ee897e78-a157-4eb5-8a47-d615096087a2.filesusr.com/ugd/113e89_e0f0aaf45f3f454c993adcaeb2e367a1.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/mukutud/fesefaniladagi.pdfIn PDF document text
    • https://s3.amazonaws.com/risalenefazozo/how_to_pair_logitech_mouse_keyboard_with_other_non-unifying_receiver.pdfIn PDF document text
    • https://5548a280-a194-4776-8019-0e256783c1fa.filesusr.com/ugd/f2c1dc_af183aab6c7043999731048cf49fea37.pdf?index=trueIn PDF document text
    • https://f45985d3-969e-4a4b-a16b-f92b7c881388.filesusr.com/ugd/20da2d_ee305e14904b46aabde0a9d2eeef209e.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/631d4086-a9ce-41b2-930b-8ceb30fedb1e/wudagesovunowujebuvopuwe.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/15a054a1-b332-4cfd-bbcf-655055822e00/dawaxekoputabalupen.pdfIn PDF document text
    • https://s3.amazonaws.com/xepululejiwof/bebeg.pdfIn PDF document text
    • https://s3.amazonaws.com/silubebebefuju/93623372200.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a8e49787-855f-40df-970b-f50cb7504427/bejuvaxukafe.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_off000109ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109FF 5516 bytes
SHA-256: c6c81b43bafa298099ad8204d0d534a8aae4798c215ccd668115e7a34f247136
font_01_sfnt_off00011ca9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CA9 12732 bytes
SHA-256: 727e30c387d8f8c56d4365f52d25aa8446b901a8907ace656c31a85ca020b2be