Malicious PDF — malware analysis report

Static analysis result for SHA-256 a0843da5dbc6e389…

MALICIOUS

PDF

135.8 KB Created: 2021-03-25 08:20:12 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: b4d25b1c2b33c52d8e2e4d41c5c60194 SHA-1: b356b4cb487793f378d1bb50435056175d4b57cb SHA-256: a0843da5dbc6e389b1738120180c67ea00d5d6409636ddf371ae2118be3fe920
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to disposable hosting, indicating a link farm designed to distribute traffic or host malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent. The embedded URL and the PDF's structure suggest it is part of a phishing or malware distribution campaign, likely using a spearphishing attachment as the initial access vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 6

  • 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 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://leonvi.ru/wix?keyword=dragon+nest+mercenary+hero+guide PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4366339/normal_60409d3009900.pdfIn PDF document text
    • https://cdn.sqhk.co/ruxunafifu/gcONif0/nasumimalitosonedufugukis.pdfIn PDF document text
    • http://gizovivomiz.getenjoyment.net/empirical_study_definition.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4414680/normal_6042892771514.pdfIn PDF document text
    • https://xutafutixon.weebly.com/uploads/1/3/4/5/134576274/bipabokotova.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4376382/normal_5ff069faa6a43.pdfIn PDF document text
    • https://cdn.sqhk.co/retesixabe/hcpijg1/rider_strong_net_worth.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4427501/normal_60262a353acfe.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4411498/normal_602da5d02596e.pdfIn PDF document text
    • http://sukuwodexi.scienceontheweb.net/blanchard_macroeconomia_7ma_edicion.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4411229/normal_5fcc82cc6fdf6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4380699/normal_60257fd393694.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4455380/normal_5ff40fe6a3909.pdfIn PDF document text
    • https://wopuxikejixup.weebly.com/uploads/1/3/1/8/131856699/3379442.pdfIn PDF document text
    • http://jesibijifinuz.mywebcommunity.org/nurani_al_quran_free_download.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4462681/normal_604b0778ec132.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4407102/normal_6043ec55ad6b1.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00013e09.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13E09 41960 bytes
SHA-256: 163d12dca7ae35d21f88db83eff84d3dfb07109cdf816356640b40052240cea9
font_01_sfnt_off0001c0ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1C0AB 5420 bytes
SHA-256: e1a6c043d76987a1aaa06e1628cde9c9beb2f1b6c88513d1e6e30497ecf7d493
font_02_sfnt_off0001d2f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1D2F8 12180 bytes
SHA-256: 1d2de0324caa49f9a90c4adbb033c45bd28208ee5d07e6ff419136046ec8673e
font_03_sfnt_off0001fcab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1FCAB 16136 bytes
SHA-256: 10496a624e1b6343f84f1e48eb6e3fcb66a8eb804010f6ab90e73e80bcd7f0b7