Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c88e508d359f974…

MALICIOUS

PDF

80.7 KB Created: 2021-05-04 06:53:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 5c9fb44077419c0b642d6aa9b5732c46 SHA-1: ddcd8a35c4a3f840fd407efb943d4f354f8db4a5 SHA-256: 8c88e508d359f97458445fa5ed523940332e1fff8ec8529bb44f93049f589e7d
126 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many of which point to disposable hosting and are used in a link farm pattern, suggesting a phishing or malware distribution scheme. The document body, though heavily obfuscated, contains references to 'wkhtmltopdf' and a date, hinting at its construction. The presence of external URIs and the overall structure strongly suggest it's designed to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://druttle.ru/strik?utm_term=ejemplos+de+investigacion+pura+y+aplicada+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4457854/normal_603ef1f562076.pdfIn PDF document text
    • http://lifelalulenomip.mygamesonline.org/thomas_calculus_early_transcendentals_solutions_manual.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4386621/normal_604ce79983c24.pdfIn PDF document text
    • https://cdn.sqhk.co/repejuvovod/1jbjdjb/putebisug.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369930/normal_5fdc291546097.pdfIn PDF document text
    • http://slimitalia.space/metro_paris_mapa8lfs5.pdfIn PDF document text
    • https://cdn.sqhk.co/tezimafi/3lkjehj/android_emulator_for_windows_7_highly_compressed.pdfIn PDF document text
    • https://cdn.sqhk.co/jututumogu/jaiaQx9/67666674880.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4405194/normal_601797ccb97c1.pdfIn PDF document text
    • https://cdn.sqhk.co/kixobaza/jaNhglQ/daycare_bed_sheets.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4501514/normal_6041946568979.pdfIn PDF document text
    • http://lnstagramcopyrightmanagement.com/graco_190es_partssw041.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4409417/normal_5fd7b91762a83.pdfIn PDF document text
    • https://cdn.sqhk.co/talexadu/enrY1ie/refewujitulikitexasizawi.pdfIn PDF document text
    • https://cdn.sqhk.co/jezumasulej/hghjwhf/86894852163.pdfIn PDF document text
    • https://cdn.sqhk.co/dofofoziga/ibrQgfV/nhtsa_sfst_manual_2019.pdfIn PDF document text
    • https://cdn.sqhk.co/nugutobudan/ciqjjcB/36539135553.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4453901/normal_602f41c176463.pdfIn PDF document text
    • http://jopkapopka.online/omega_xl_walmart_near_menl3wg.pdfIn PDF document text
    • https://cdn.sqhk.co/xujurovemu/iLibDGB/69589287059.pdfIn PDF document text
    • http://banademebilite.sportsontheweb.net/zeziwifiwuzo.pdfIn PDF document text
    • http://mobufuwiwid.medianewsonline.com/pictionary_words_easy.pdfIn PDF document text
    • https://cdn.sqhk.co/gorokipo/ipia6E4/catbird_seat_slang_definition.pdfIn PDF document text
    • http://f13x.xyz/the_broken_shore_investigating_the_legion_guidect1oa.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4447464/normal_606ea8f10fcae.pdfIn PDF document text
    • http://fontawesome.iohttp://fontawesome.io/license/In PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://xekapakifujekem.onlinewebshop.net/52574724762.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f124.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF124 1872 bytes
SHA-256: 31c540d11144f4345156f451af9ba389a1131d21873ea1c3280cece25ef53112
font_01_sfnt_off0000fa18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA18 5668 bytes
SHA-256: f65e6afa4d3a84eaf204be0b539c5fe1d9e2983d4754ed27b007c40eefadaa9a
font_02_sfnt_off00010d65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D65 11396 bytes
SHA-256: 0dc3cb14290a18be3c9033b4c38de5a48cffba03763054894c0a7f581af8cefa