Malicious PDF — malware analysis report

Static analysis result for SHA-256 84066f4c939dfa1b…

MALICIOUS

PDF

36.9 KB Created: 2020-06-26 00:00:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 82d26ee5fd067ee0bd23823354884e75 SHA-1: fd9b99bc9574f0bda20142925e9dc62919c3bef3 SHA-256: 84066f4c939dfa1b0a764c4e4bc3b46b7dd89591151190c165b295b0183445a9
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a large number of embedded links to external PDF documents, a technique often used for SEO manipulation or to distribute further malicious content. The ML classifier strongly flagged this PDF as malicious, and the heuristic 'PDF_SEO_LINK_FARM' confirms the presence of a mass external link farm. The primary purpose appears to be redirecting users to a network of other documents.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • 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.
  • 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 http://blakheart.com/uploads/1/3/0/5/130546977/130546977.html#bs+5950+part+3+pdf
    • http://thegroovyvegan.net/uploads/1/3/0/8/130874679/a39d85dd7418f1d.pdf
    • http://tammybiggsgymnastics.org/uploads/1/3/0/4/130483062/2193119.pdf
    • http://mail.thefrontpaige.com/uploads/1/3/0/6/130639116/rivipipajenu_tinebazanigi.pdf
    • http://mpd11.bpmtc.com/uploads/1/3/0/2/130287882/9085cd.pdf
    • http://mx.sandimaswines.com/uploads/1/3/0/5/130589064/lupapilewofabagelom.pdf
    • http://mta-sts.mx.harveyswaterwells.com/uploads/1/3/0/9/130969960/3014362.pdf
    • http://boricuando.org/uploads/1/3/1/8/131856173/pevunup.pdf
    • http://violetcrownkids.com/uploads/1/3/0/3/130313459/sijofomuremirixubi.pdf
    • http://thecustomartisan.com/uploads/1/3/1/4/131453902/xepulajuz.pdf
    • http://webmail.indie-pendant.com/uploads/1/3/1/4/131455475/pigoxugi.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://budekukagok.files.wordpress.com/2020/06/xenomamigemidok.pdf
    • https://xalemogewal.files.wordpress.com/2020/06/39146873495.pdf
    • https://puxekagoduse.files.wordpress.com/2020/06/84445156485.pdf
    • https://pujobat.files.wordpress.com/2020/06/76147913454.pdf
    • https://gonaburezi.files.wordpress.com/2020/06/zevaz.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005224.bin
29879959b6fcfdb715f163e5bc8e324f03714e21b9e16a68132ca1ee8467865b
pdf-font-stream PDF embedded font (sfnt) at offset 0x5224 5044 bytes
font_01_sfnt_off00006341.bin
955a8a8b73d8c82f9b3fe7a013890aa13c33a53eab5bf469df4081c83219123c
pdf-font-stream PDF embedded font (sfnt) at offset 0x6341 10516 bytes