Malicious PDF — malware analysis report

Static analysis result for SHA-256 85136d0668c4cad5…

MALICIOUS

PDF

77.8 KB Created: 2021-03-21 06:10:57 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: 69954f2bdec126bc1cc5aafd67bfdb67 SHA-1: dbd8259fe1c6d28e87725500e8bfeb267f16f66e SHA-256: 85136d0668c4cad5c049fbe8609159eb6d042a23897e19a71bae1689275c0f17
126 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous external links, with a primary one pointing to 'https://zajinet.ru/wix?keyword=aicp+exam+study+guide', suggesting a lure to a malicious website. The document body is heavily obfuscated and unreadable, but the presence of external links and the overall heuristic firings strongly suggest an attempt to redirect the user to a compromised or malicious site.

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://zajinet.ru/wix?keyword=aicp+exam+study+guide PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4476270/normal_6019143b49a88.pdfIn PDF document text
    • https://kobuxomibusopi.weebly.com/uploads/1/3/4/6/134609859/2366810.pdfIn PDF document text
    • https://foduvixet.weebly.com/uploads/1/3/4/4/134498725/pewulibewumava.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4365551/normal_600b590adddb3.pdfIn PDF document text
    • http://dazavaluk.mygamesonline.org/cranial_cavity_anatomy.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4392667/normal_5fe2d1f6983da.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4408335/normal_5ff3c5445a602.pdfIn PDF document text
    • https://degubazof.weebly.com/uploads/1/3/5/3/135304991/7071241.pdfIn PDF document text
    • https://togutugu.weebly.com/uploads/1/3/4/6/134617883/zoraxib-folew.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4447093/normal_6048cc67c9471.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4425235/normal_5fd9b7a722eef.pdfIn PDF document text
    • https://nidabiweni.weebly.com/uploads/1/3/4/8/134865500/2731020.pdfIn PDF document text
    • https://zesaxigupube.weebly.com/uploads/1/3/4/0/134016892/683dfe92ba39.pdfIn PDF document text
    • http://ziwusis.getenjoyment.net/dr_scholls_foot_spa_plus_manual.pdfIn PDF document text
    • https://lorukadewe.weebly.com/uploads/1/3/4/3/134348028/sopuke.pdfIn PDF document text
    • https://mitamegupep.weebly.com/uploads/1/3/2/3/132302953/ae8b5a8fd6e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4499309/normal_6053ecafc019b.pdfIn PDF document text
    • http://miromawetibikew.mywebcommunity.org/why_is_my_shower_beeping.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4451348/normal_60544423c5e73.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4402948/normal_5fe928ac1590b.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/wopari/11053992508.pdfIn PDF document text
    • https://s3.amazonaws.com/satudifin/checklist_format_in_excel_2007.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_off0000f3fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3FA 5424 bytes
SHA-256: 472244b72d6bd1a4391c78237f48444481bbf789cf863749247994e1c1d50ccf
font_01_sfnt_off00010673.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10673 10500 bytes
SHA-256: c2f246dbdb90ad53b93447760825efa03cead4160b191103b19deb1aefa79478