Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a92a1a777aced63…

MALICIOUS

PDF

76.5 KB Created: 2021-09-16 06:11:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 2604d92b1ddb2936207d29da20d7c1a9 SHA-1: 8bcbb5ec7e58d55457fa486e9860394a94953861 SHA-256: 8a92a1a777aced632741e8c21e8eba6ddd10e6fb974938a0209280129f6890e1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and heuristic firings are consistent with techniques used to host malicious content or redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://laborke.ru/uplcv?utm_term=stream+from+linux+to+android PDF link annotation
    • https://sporyolu.com/resimler/files/mubofajewim.pdfIn PDF document text
    • https://ichapps.peaceofworld.com/ichapps/ckeditor-ckfinder-integration/uploads/files/fakepuxoru.pdfIn PDF document text
    • http://avstralianature.ru/ckfinder/userfiles/files/40762264809.pdfIn PDF document text
    • http://prograsifkalip.com/files/xusobenigu.pdfIn PDF document text
    • http://centrons.com/uploaded/file/4898048496130e2c2d66ca.pdfIn PDF document text
    • http://0851gay.org/userfiles/202109file/2021091419250470554.pdfIn PDF document text
    • http://bongoes62.dk/userfiles/file/rawasa.pdfIn PDF document text
    • https://www.pepinieres-gey.fr/ckfinder/userfiles/files/84436491091.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161377aad88b5f---dojebawigexifodibomumiwod.pdfIn PDF document text
    • https://altaamir.ipixpms.com/Rapport/public/assets/ckfinder/userfiles/files/godisazegakibelepubazuvof.pdfIn PDF document text
    • http://foto-recepty.sk/images/fotky/komilixobizejeweguxodatag.pdfIn PDF document text
    • https://gulertrafik.com/wp-content/plugins/super-forms/uploads/php/files/vmsbliof7ani6q7500jij9cvjh/85941855950.pdfIn PDF document text
    • https://bccphil.paramedix.biz/uploadfiles/file/guvosatesunuxavije.pdfIn PDF document text
    • https://nyig.com/files/file/62385694053.pdfIn PDF document text
    • http://klwas.org/userfiles/images/file/48920392497.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/39lr7nobpr0e36tcn6s0lfprr4/31335773699.pdfIn PDF document text
    • https://mp2020.csysadmin.com/ckfinder/userfiles/files/ralolusapexelusax.pdfIn PDF document text
    • https://serpavenger.com/ckfinder/userfiles/files/97383514358.pdfIn PDF document text
    • http://ticketsperiodico.com/galeria/files/91343177042.pdfIn PDF document text
    • https://lashmakerpro.it/wp-content/plugins/super-forms/uploads/php/files/kpfas3l9ed84vu7i1vnkp7j2p3/51802963213.pdfIn PDF document text
    • https://europartner2.pl/uploads/bajimiwijafad.pdfIn PDF document text
    • https://bya-ingenieria.com/ckfinder/userfiles/files/85793170682.pdfIn PDF document text
    • https://www.rt9.rspo.org/ckfinder/userfiles/files/63608541122.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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c728.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC728 10624 bytes
SHA-256: 125a4ea59d3dfb326645ec1c1d1b273a6e28e3ea22ba1af242698994c7d69733
font_01_sfnt_off0000df71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF71 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f783.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF783 17432 bytes
SHA-256: cfb93d98afb31741e013e6bf3b8f63504d39a5b21ac9aabeed0c7d857fd8e261