Malicious PDF — malware analysis report

Static analysis result for SHA-256 170ef1b79265af22…

MALICIOUS

PDF

81.0 KB Created: 2021-04-05 04:10:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: 6424e64188814830f6aa8112de734a95 SHA-1: 73c12ccfc1768ac568a0ddcb553c59bcdd8194cb SHA-256: 170ef1b79265af22332dee8a78bf528f626d107676ffced119072913d047de71
126 Risk Score

Malware Insights

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

This PDF document contains a large number of external links, many of which are hosted on disposable domains or link farms, suggesting a SEO spam or phishing campaign. The document body is heavily obfuscated, but the presence of 'Avg vpn free trial' hints at a lure. While no scripts were explicitly extracted, the PDF structure and heuristic firings indicate it's designed to redirect users to malicious or spammy websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://jacksth.ru/123?utm_term=avg+vpn+free+trial PDF link annotation
    • https://mizevazorabij.weebly.com/uploads/1/3/5/3/135347525/c9087710.pdfIn PDF document text
    • https://vewefididijos.weebly.com/uploads/1/3/4/5/134517371/3880881.pdfIn PDF document text
    • https://cdn.sqhk.co/gufojakig/Egi3hbX/20357303536.pdfIn PDF document text
    • https://cdn.sqhk.co/berirenike/8KO9Njg/78744523825.pdfIn PDF document text
    • https://cdn.sqhk.co/zivalutapa/I8hihbC/97665505834.pdfIn PDF document text
    • https://lurusavi.weebly.com/uploads/1/3/2/7/132710630/soruxibenepajum_vigimora.pdfIn PDF document text
    • https://cdn.sqhk.co/zasokolof/gimtZhe/nfs_heat_studio_app.pdfIn PDF document text
    • https://cdn.sqhk.co/miranilu/4dxjekX/ez_loader_trailer_marker_lights.pdfIn PDF document text
    • http://digtalcaliper09.xyz/is_ap_art_hardw1dcc.pdfIn PDF document text
    • https://cdn.sqhk.co/nulusezitelo/PaG6igG/account_balance_definition_audit.pdfIn PDF document text
    • http://maxist.ru/2655345133hv7v4.pdfIn PDF document text
    • http://migriruy.ru/xagolesip0sd0c.pdfIn PDF document text
    • https://cdn.sqhk.co/wozovege/3O7xjdg/formal_email_writing_format.pdfIn PDF document text
    • http://stebsmeh.space/atividade_reportagem_9_anoqk9g3.pdfIn PDF document text
    • http://creditstar-kabinet.com/15783899304358sa.pdfIn PDF document text
    • https://cdn.sqhk.co/dabozijide/ohggcxa/maine_lobster_trap_coffee_table.pdfIn PDF document text
    • https://cdn.sqhk.co/wazafanez/ijilij9/gitilijogotodesasofedoxef.pdfIn PDF document text
    • https://cdn.sqhk.co/zukuxenopo/i6LdBhc/ropanovajusetuxopixomude.pdfIn PDF document text
    • https://cdn.sqhk.co/putuziboki/hjeAifr/poly_jigsaw_low_poly_art_puzzle_games.pdfIn PDF document text
    • https://cdn.sqhk.co/noxuwitide/Q4Ojj1W/chaos_rings_iii_prequel_trilogy_english_patch.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/93159caa-8ff0-4374-9a41-1fcfc24ac1d6/microsoft_excel_spreadsheet_online_course.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/25e5ec85-a5b1-4ac6-8099-87e91d4aea00/cub_cadet_lt1042_parts_diagram.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9daebad5-f393-4298-876d-a89373dd6fd1/perfect_english_grammar_phrasal_verbs_4.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/01a8a5fc-d71c-4af4-bd8e-6bf86c11d518/old_school_runescape_mobile_buy_gold.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ec3f6fd7-f88d-45ac-8e5b-979f27ba7768/48360031614.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_off0000ffb0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFB0 4940 bytes
SHA-256: 448fd0fcc8c07f83d445c08af288168df4e67cf13f1f7c68820c237135612279
font_01_sfnt_off000110a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110A2 10964 bytes
SHA-256: b94edacaa95a06c124861feb0f3e0161745c9f0494042af4b57fab8cc99bc842