Malicious PDF — malware analysis report

Static analysis result for SHA-256 51a81e3c770269fc…

MALICIOUS

PDF

79.1 KB Created: 2021-03-14 01:02:10 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-18
MD5: d2ce08720fd37771bc17a6e7ca9f1da1 SHA-1: 72465d4040eeab1826ec014221d9c7daa7dcc752 SHA-256: 51a81e3c770269fc28d18a3dc273683fec594ebfd14d00f8202f92aebc8ae31d
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

This PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier indicating maliciousness. The presence of a 'Clipboard command execution lure' heuristic suggests the document instructs users to copy and paste commands into a shell. This, combined with embedded URLs pointing to potentially malicious content, indicates an attempt to trick the user into executing a secondary payload. The document's structure and embedded links suggest it is part of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Clipboard command execution lure high SE_CLIPBOARD_COMMAND_LURE
    Document tells the user to copy or paste clipboard content into Run, PowerShell, cmd, or another shell-like execution context
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://zajinet.ru/123?utm_term=java+jre+10.+0.+2 PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4383797/normal_60234ca2e9035.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450424/normal_602de69d90a0d.pdfIn PDF document text
    • https://cdn.sqhk.co/bisidilit/gdCgjic/doom_2_levels_ranked.pdfIn PDF document text
    • http://zokugorevat.mywebcommunity.org/how_do_you_share_a_document_on_facebook.pdfIn PDF document text
    • http://xazonem.22web.org/crash_course_bicameral_congress_answers.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4384480/normal_600b36fb6efce.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4443624/normal_5fe7f2e9422cc.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403541/normal_602c7676a4ce3.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4460460/normal_5febe10f766f3.pdfIn PDF document text
    • http://lazategomid.scienceontheweb.net/14078461164.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387709/normal_6049937896f36.pdfIn PDF document text
    • http://xevusezes.medianewsonline.com/93654762789.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4443824/normal_5ff65f58bb743.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387054/normal_5fd203dbdbd15.pdfIn PDF document text
    • https://cdn.sqhk.co/wuzosiboweja/dzjhagc/comedy_movies_to_watch_on_netflix_bollywood.pdfIn PDF document text
    • http://ziwefewixus.iblogger.org/sawonitadokogelon.pdfIn PDF document text
    • http://dimozakebaba.scienceontheweb.net/99508593421.pdfIn PDF document text
    • https://cdn.sqhk.co/virurewev/oDyhalw/connect_crewlounge_aeropuerto.pdfIn PDF document text
    • http://ponemofetu.scienceontheweb.net/dns_323_firmware_1.09_download.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4378848/normal_5fc87b285918c.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://xovanesoku.epizy.com/demosizavemapobagomox.pdfIn PDF document text
    • http://pikaderobiw.atwebpages.com/a._v_aids.pdfIn PDF document text
    • http://sabiwilurase.atwebpages.com/nakotiditorovelu.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_off0000f6de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6DE 4952 bytes
SHA-256: 5896e3001b784efe0056a8b4b76fb7736c2ccc35ff41a7b9f6d4461386a585b7
font_01_sfnt_off000107e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107E0 11596 bytes
SHA-256: b37313011b2f8f0f3c9cced580961b025bad80538935600793014d18e93ce64f