Malicious PDF — malware analysis report

Static analysis result for SHA-256 51979b5fc96e3abd…

MALICIOUS

PDF

76.6 KB Created: 2021-03-24 11:31:42 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: dc8cabad057e8b78c703c3590b9076ae SHA-1: 33c51b35c26ef8e7b61e63c509955d9f6c9a54c0 SHA-256: 51979b5fc96e3abdfa8ff1eaa3cd73abb332ac02cad5c7065cf48ded80368d86
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, with one prominent URL pointing to 'vilenefex.ru' and a query parameter suggesting a lure related to 'latest android games apk data'. The document body, though heavily obfuscated, contains metadata that aligns with this lure. The presence of multiple external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic indicate a strong intent to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://vilenefex.ru/123?utm_term=latest+android+games+apk+data PDF link annotation
    • http://goldenframecollision.com/boston_market_chicken_soup_caloriesaou0r.pdfIn PDF document text
    • https://cdn.sqhk.co/lokabawopup/niaMZih/beat_street_movie_trailer.pdfIn PDF document text
    • https://cdn.sqhk.co/zopizote/69Rifjd/66207050552.pdfIn PDF document text
    • http://runavowof.22web.org/ionic_4_action_sheet_css.pdfIn PDF document text
    • http://bitjoms.xyz/performance_review_examples_for_leadership7b2lm.pdfIn PDF document text
    • https://cdn.sqhk.co/vixukose/jgaiaij/wilenenuwidupepisenajak.pdfIn PDF document text
    • http://drenajkrasnodar.ru/kuzavarilanokedugogabuz6jn9l.pdfIn PDF document text
    • https://cdn.sqhk.co/rosomugimo/ePngg6T/mtb_downhill_multiplayer_apkpure.pdfIn PDF document text
    • https://cdn.sqhk.co/bisidilit/jiigIig/wabexi.pdfIn PDF document text
    • http://discount50.pro/10954368945gm6rm.pdfIn PDF document text
    • https://cdn.sqhk.co/govuzupikiwe/rgipxgf/halloween_wallpaper_cute_iphone.pdfIn PDF document text
    • https://cdn.sqhk.co/nilamemiw/jaswVOJ/mini_militia_unlimited_speed_mod_apk_download.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://0e818273-c791-4c7a-b20f-750474b78fe4.filesusr.com/ugd/362633_f9decf571e4e446795b28a6e59b68956.pdf?index=trueIn PDF document text
    • http://xewarokulix.rf.gd/photoshop_cc_2019_brushes_free.pdfIn PDF document text
    • http://xisirajotijejuw.rf.gd/degasovumeson.pdfIn PDF document text
    • https://ba30dffa-51fe-4caa-9472-6f142403a9bb.filesusr.com/ugd/c2007e_405bd6b3b9c747bf836f3cbc23da9061.pdf?index=trueIn PDF document text
    • https://fbaba6ab-37cf-477f-82bd-e10a416eccda.filesusr.com/ugd/3c8574_f15c6329076746e5a0f7ef4e43f51506.pdf?index=trueIn PDF document text
    • https://1b3e2d6a-0348-4772-9bb2-16e56a761455.filesusr.com/ugd/7bcf02_6d18ea7f23844642a33a283c524e3045.pdf?index=trueIn PDF document text
    • https://55f5e71c-5f54-469f-9449-301c43944234.filesusr.com/ugd/bbdb65_a87cd7eedd5c4bbf898e4e9eda120736.pdf?index=trueIn PDF document text
    • http://limixumijegaf.epizy.com/camber_caster_toe_in_toe_out.pdfIn PDF document text
    • http://wewojujimijanu.rf.gd/breville_toaster_oven_bov800xl_canada.pdfIn PDF document text
    • http://sulosuduvemog.epizy.com/pimimuw.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_off0000df68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF68 5040 bytes
SHA-256: 81821fe12175df3a515aa769813009d3bcc9f7e02142793ae7273c2764c5eba5
font_01_sfnt_off0000f071.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF071 11192 bytes
SHA-256: 5b36b4691c81dfaeeeed357a7ff552847d58863ff1d883d520985bf01be8ec38
font_02_sfnt_off0001169a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1169A 4324 bytes
SHA-256: a542ec26cea93e049a2e27cd59b1347dd9bbdea13775fd7b822b3c2b3136116f