Malicious PDF — malware analysis report

Static analysis result for SHA-256 71cb356db0baf07d…

MALICIOUS

PDF

83.7 KB Created: 2021-06-10 14:17:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-02
MD5: eaf511eadbf9f55249db8e338923089c SHA-1: ca90fefb5929b55d9a89229a3dc7f86c72f380c3 SHA-256: 71cb356db0baf07da3b6f4365075064c5ea817f8a85f9ce375cca6338beb84a6
196 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses a password-protected-archive lure. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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://garglob.ru/uplcv?utm_term=bts+love+yourself+her+album+download PDF link annotation
    • https://www.nestroots.com/wp-content/plugins/super-forms/uploads/php/files/1cirfosbrek4h00ic676vn6ou2/50381244811.pdfIn PDF document text
    • http://generaltubi.com/container/ckfiles/files/59308135886.pdfIn PDF document text
    • https://monyetmesum.com/contents//files/68043717168.pdfIn PDF document text
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081c2964e095---dazidazafukitan.pdfIn PDF document text
    • https://xn----7sbbjg7ctfs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/b33aa9482d2b4b3bacab2d6664801aae/99766305673.pdfIn PDF document text
    • http://www.jamesbgriffinlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc6f2b2ea04---25529094154.pdfIn PDF document text
    • https://webtraffic.ch/wp-content/plugins/super-forms/uploads/php/files/ssfba269oahim6bdb3mp5ujhqj/95404826712.pdfIn PDF document text
    • http://fitviewer.biz/files/file/zagamowudivozofibudime.pdfIn PDF document text
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c22e021d67---sigizake.pdfIn PDF document text
    • http://pnktools-th.org/ckfinder/userfiles/files/kutorokuxefumekixujov.pdfIn PDF document text
    • https://amerismithenterprises.com/wp-content/plugins/super-forms/uploads/php/files/9d839a5816f099875216c77094ed8de1/bajuwa.pdfIn PDF document text
    • http://usmleworkout.com/files/file/75908480887.pdfIn PDF document text
    • https://agentcctv.com/userfiles/file/nomimifosevixubux.pdfIn PDF document text
    • https://vetranhtuongmamnon.vn/wp-content/plugins/super-forms/uploads/php/files/f4ti0frkofqbbul98posqjru7g/22772633668.pdfIn PDF document text
    • http://krevue.cz/UserFiles/File/38803069179.pdfIn PDF document text
    • https://aannemingsbedrijfbarthulsbosch.nl/userfiles/file/37764029960.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

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ee24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE24 6632 bytes
SHA-256: b9d0b738a0d0070502d78f16239084af0fe5959442d67054d36eef17b433dc03
font_01_sfnt_off000104dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104DD 5592 bytes
SHA-256: 5c5c815e3a93b7f6a3d0230e6dcd21b5022a06b83cb044fe8b35f36a474cee53
font_02_sfnt_off000117ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117CA 12328 bytes
SHA-256: 87679bda245be650e341706f10eefa057c95fde12eb1fdc47947c4c1ed31044e