Malicious PDF — malware analysis report

Static analysis result for SHA-256 786b5de8ccd5408d…

MALICIOUS

PDF

77.4 KB Created: 2021-03-23 18:58:08 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 8a98d93f44374d9919abc6da9fb0d7a8 SHA-1: 5246e4275ff6a657c2137a512d5f290018d2b322 SHA-256: 786b5de8ccd5408dad298cb96dab965f784ebcd900897c3f80c83a9ade62824f
126 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The embedded URLs and the PDF's structure suggest it functions as a link farm designed to redirect users to potentially malicious sites, with one URL specifically mentioning a browser download. The presence of numerous external URIs and a link farm heuristic further supports this. The document body, though heavily obfuscated, contains references to 'Opera browser' and 'windows xp', reinforcing the lure of a software download.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://resalured.ru/123?utm_term=opera+browser+windows+xp+32+bit
    • http://dosijefa.mypressonline.com/english_conversation_business_meeting.pdf
    • http://digitalcalakk1.xyz/3160507285hwu39.pdf
    • http://kudretbozaci.com/jlab_jbuds_charging_casegvp8e.pdf
    • https://cdn.sqhk.co/fekurisakez/Bdjijfm/30881439142.pdf
    • http://mokemowowove.mygamesonline.org/32565626951.pdf
    • https://cdn.sqhk.co/kawiwitifa/jNih0pD/xumiwisaxalujaxodumiv.pdf
    • http://garanibukumom.scienceontheweb.net/2010_chevy_malibu_power_steering_pump_location.pdf
    • http://libopadu.scienceontheweb.net/biomes_of_north_america_pogil_answer_key.pdf
    • http://kolagozisil.mywebcommunity.org/cutting_edge_pre_intermediate_teacher_s_book_free_download.pdf
    • http://ladiluvame.mypressonline.com/jusiparoralet.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://s3.amazonaws.com/fifuto/imf_annual_report_2019.pdf
    • https://1ebfeea1-7d02-43b8-8f0a-002c87bc7f75.filesusr.com/ugd/50dcf6_99ccfdf2be7146fc8c3ea13bdd6a2b53.pdf?index=true
    • https://95fbbc11-640f-4658-acdf-6e09da746871.filesusr.com/ugd/e42ee3_ae7e2cb77f494d31b0f2244690e05422.pdf?index=true
    • https://148d48ef-a78d-4e34-a4d2-755cfbac042a.filesusr.com/ugd/ccca9b_05504a6e5853498ca9ec1f93678f8765.pdf?index=true
    • https://s3.amazonaws.com/vonutavekip/mipuf.pdf
    • http://womidelere.myartsonline.com/vaburune.pdf
    • https://s3.amazonaws.com/davolazupivowi/50060637781.pdf
    • https://s3.amazonaws.com/lazolu/what_is_classical_greek_sculpture.pdf
    • https://s3.amazonaws.com/zuguvoxoki/dapijugufefewoni.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e30f.bin
7f9a3c21d0c38e81a8d3e36d0a02aad8a96acd26f86899f6c4ccd5f213288f9c
pdf-font-stream PDF embedded font (sfnt) at offset 0xE30F 5332 bytes
font_01_sfnt_off0000f543.bin
b019865b5f35de33eed435a81a07c37a37111000fcae339c1dbb9adddf547610
pdf-font-stream PDF embedded font (sfnt) at offset 0xF543 10892 bytes
font_02_sfnt_off00011a9d.bin
b50a2106bf82917db0cd3cf88f63c5e8cc3298b343ace5cffc591b35df33d24c
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A9D 4324 bytes