Malicious PDF — malware analysis report

Static analysis result for SHA-256 77cfbe3d4058af60…

MALICIOUS

PDF

83.1 KB Created: 2021-09-11 17:19:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: ec2fecd3030e36bf3b6ec2b0d5cec867 SHA-1: 2e09f7bc4363f8c3fbe79dd6b99395166f3ad2c8 SHA-256: 77cfbe3d4058af606a3b238bf9ed3cd6d0e0b3eb4da8aa5a1db7988bea731a6d
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged as malicious by ClamAV and an ML classifier. It contains embedded JavaScript and a large number of external URIs, many of which are hosted on disposable domains and appear to be part of a link farm. The presence of embedded JavaScript suggests an attempt to execute malicious code, likely to redirect the user to a phishing site or download further malware. The numerous links, some with UTM parameters, indicate a broad distribution effort.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://wastran.ru/uplcv?utm_term=iptv+m3u+links+2021 PDF link annotation
    • http://wignaccent.com/FCKeditor_2.6.3/userimages/file/20210901173104.pdfIn PDF document text
    • http://revistaspontan.ro/assets/ckfinder/core/connector/php/uploads/files/jejosolutorubuv.pdfIn PDF document text
    • https://rarahil.org.np/ckfinder/userfiles/files/tosivabo.pdfIn PDF document text
    • http://rotarytattoomachine.co/project-new/christianbook/upload_images/file/49949349030.pdfIn PDF document text
    • http://ux02.wadhost.com/js/ckfinder/userfiles/files/65677295604.pdfIn PDF document text
    • http://phutungvespaco.com/luutru/files/78122279020.pdfIn PDF document text
    • http://wwm-quanta.com/upload/files/41332888004.pdfIn PDF document text
    • https://vntdc.com/upload/fck/file/87659327806.pdfIn PDF document text
    • http://thayloilocnuoctaihanoi.net/upload/files/busafunixiboveres.pdfIn PDF document text
    • http://wiskind.com/filespath/files/20210910194851.pdfIn PDF document text
    • https://nucamsa.es/userfiles/files/14520011154.pdfIn PDF document text
    • https://mattress-leader.com/media/55430875513.pdfIn PDF document text
    • http://nnk.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1613c93e45730e---vakozadipokefetak.pdfIn PDF document text
    • http://stellamaris.cz/userfiles/77024332827.pdfIn PDF document text
    • http://olguanaokulu.com/upload/file/vupibebiviwapojoreb.pdfIn PDF document text
    • http://kdwatch.net/upload/files/2021091109555024.pdfIn PDF document text
    • https://darshanam.com/ckfinder/userfiles/files/zunewevarafot.pdfIn PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/16134526d882c2---80435593523.pdfIn PDF document text
    • http://eatoceanic.iorderfoods.com/uploads/files/retukin.pdfIn PDF document text
    • https://donnasalon.ru/wp-content/plugins/super-forms/uploads/php/files/35c5c41360bf555a84a4ca1004c162c5/zagokexez.pdfIn PDF document text
    • https://tideandtigers.com/ckfinder/userfiles/files/10811740125.pdfIn PDF document text
    • https://insinkerator.us/images/uploaded/file/jabumixumemofirabuvidusi.pdfIn PDF document text
    • http://pampa.be/uploads/userfiles/files/7557113995.pdfIn PDF document text
    • https://satnamunicipalcorporation.com/admin/ckfinder/userfiles/files/tibupujedatagepuxep.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_off0000dfdd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFDD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f7ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7EF 18152 bytes
SHA-256: 2ed265807030fa3c577c7b64f504f1832c5adae51d0c14c6b090f64304eaec74
font_02_sfnt_off000126fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126FA 10572 bytes
SHA-256: 83a9a431a1e3fbd486f409cba754146f0f6c833d1182b90c9a04a23c56dacfb7