Malicious PDF — malware analysis report

Static analysis result for SHA-256 ae50a741e4aa0999…

MALICIOUS

PDF

72.2 KB Created: 2021-06-18 18:02:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-26
MD5: 4541c8b9a22d5a23a579baffbb206a60 SHA-1: d143d619d0362c9f8a0db23e5ad69b8a93932da9 SHA-256: ae50a741e4aa0999d843d5703c89e07a0f454de362c2de57824c5770050a1509
156 Risk Score

Malware Insights

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

This PDF was identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. It functions as a link farm, with numerous URLs pointing to compromised WordPress sites that host additional PDF files. These secondary PDFs are likely designed to further phishing attempts or distribute malware. The presence of multiple external URIs and the compromised CMS upload link farm heuristic strongly support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://vasilii-orlov.fun/wp-content/plugins/super-forms/uploads/php/files/5ed11c103caf2ea0e4b9e954edf5a06b/77154538342.pdf In PDF document text
    • https://swotin.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b73ba178210---98887104883.pdfIn PDF document text
    • https://www.ideaklinikbursa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078ad7dd0b39---rudovamunaw.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/f0v0gugccdtqss306q176tk342/gojizale.pdfIn PDF document text
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/8g6o2ih2d7eslgupajb0vle25t/wafolefugopagojatupuxe.pdfIn PDF document text
    • https://rjiminfra.com/wp-content/plugins/super-forms/uploads/php/files/397cddb1d3c51ab4f0addb92a2123a6a/63724643453.pdfIn PDF document text
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/3e657918e8f275f3717d65f4c6babf35/dekalejaxosazuj.pdfIn PDF document text
    • https://gerastar.com/userfiles/file/bekazosukafavatav.pdfIn PDF document text
    • https://susta.vn/userfiles/file/timekine.pdfIn PDF document text
    • https://sunwayhk.com/louis/STARKGROUP/ckfinder/userfiles/files/wanupokikene.pdfIn PDF document text
    • https://sandzak.best/wp-content/plugins/super-forms/uploads/php/files/a8d58d588ddfce842048b68e874ae9d2/44374482458.pdfIn PDF document text
    • http://mosjob.ru/images/file/kevetu.pdfIn PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/civa5ptqb5jjelufkm51prg160/balizigivital.pdfIn PDF document text
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/852200e804ecd8e4e72bfd71fc1e6a31/bisorab.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=practice+derivatives+worksheetPDF link annotation
    • 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_off0000d0b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0B1 4896 bytes
SHA-256: 22789f0abc8b9f74775234e121662889f7bc86677c9486e4d7e1219adc3b4089
font_01_sfnt_off0000e173.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE173 10684 bytes
SHA-256: 3e5e4ea34f68be240544e1e78119cf8c96e9e14217c668d63f3a553fabe45ce6
font_02_sfnt_off000105d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105D5 4324 bytes
SHA-256: a542ec26cea93e049a2e27cd59b1347dd9bbdea13775fd7b822b3c2b3136116f