Malicious PDF — malware analysis report

Static analysis result for SHA-256 100f13c4f869775e…

MALICIOUS

PDF

77.0 KB Created: 2021-04-02 02:39:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 8bd632b937006d4d8a08c7e1ad3a318e SHA-1: 05999f465fddc8d9c2ae0f7dee9ffdeeefb106c6 SHA-256: 100f13c4f869775ec37609ae50de6e07c86f657a3e2ba13b6092d3131667ee3a
126 Risk Score

Malware Insights

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

This PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a phishing or trojan payload. It contains numerous external URLs, with one specifically pointing to a resource that appears to be a lure for an 'excel template for class schedule'. The presence of multiple disposable hosting links and UTM parameters suggests a campaign focused on redirecting users to malicious content. No scripts were extracted, but the PDF structure itself is being leveraged to host malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • 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 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://botokaw.ru/123?utm_term=excel+template+for+class+schedule
    • https://cdn.sqhk.co/nosilaxuziz/3hjiehc/78550230068.pdf
    • http://edayafar.xyz/aws_solution_architect_cheat_sheet_2020iwbfr.pdf
    • https://cdn-cms.f-static.net/uploads/4365599/normal_6038df5a51669.pdf
    • http://uplrezina.site/samsung_nu8500_curved_4k_uhd_smart_tv_55-inchr5smg.pdf
    • https://cdn-cms.f-static.net/uploads/4490722/normal_6011e38f5f21b.pdf
    • http://smartradiobf.ru/tavenuragukobefisg2jg.pdf
    • https://cdn.sqhk.co/posukomokufi/3pbBja1/nostalgia_gbc_gbc_emulator_pro_apk.pdf
    • http://gufutaca3.xyz/accident_reports_nc_state_highway_patrolr8kmw.pdf
    • https://cdn.sqhk.co/puranajav/ivjh1f7/6035166850.pdf
    • https://cdn-cms.f-static.net/uploads/4449996/normal_5fdaac44e1f32.pdf
    • https://cdn.sqhk.co/vawadawuleja/bgjhgjg/68323137268.pdf
    • https://cdn.sqhk.co/nujamaweke/UuihLoM/zombie_invasion_monster_trucks.pdf
    • https://cdn-cms.f-static.net/uploads/4389809/normal_6034e02d2ecdb.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://mumitojeda.rf.gd/clinical_biochemistry_book_download.pdf
    • https://s3.amazonaws.com/zevutebulaworel/business_information_systems_jobs_salary.pdf
    • https://uploads.strikinglycdn.com/files/8525d300-7365-46f2-bab6-c73013f3048e/m_408_portable_super_bass_wireless_bluetooth_speaker_-_full_metal.pdf
    • http://nivawuxiki.rf.gd/28099816392.pdf
    • https://uploads.strikinglycdn.com/files/476071e7-22c2-4720-978d-50b6866c85ba/chicco_bravo_for_2_stroller_weight.pdf
    • https://uploads.strikinglycdn.com/files/266673e5-a70b-4989-81b7-161f779cd667/61125454036.pdf
    • https://s3.amazonaws.com/vebisop/79446509690.pdf
    • https://uploads.strikinglycdn.com/files/4255aa7d-6d1f-47b2-935c-2c37067c1f47/5564903406.pdf
    • https://s3.amazonaws.com/nakuzafol/92382772836.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ed40.bin
40d0efed5396a095c39f818ee1ef1728949f36fc367215912f604a62c7dfa926
pdf-font-stream PDF embedded font (sfnt) at offset 0xED40 5420 bytes
font_01_sfnt_off0000ff87.bin
975b09db3e840f136b73a60a37f6b1c27f5e4d8ad7a1e3865a3df931daaffb3d
pdf-font-stream PDF embedded font (sfnt) at offset 0xFF87 11140 bytes