Malicious PDF — malware analysis report

Static analysis result for SHA-256 c61017e884da578d…

MALICIOUS

PDF

68.1 KB Created: 2021-09-30 21:38:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: ee8d72789f2f72ae75a93410c9ad193f SHA-1: 4ff19f1768db30d37930d82bcbe2092955b5b39e SHA-256: c61017e884da578dceb4928d2fe6b1109407324b89ce73a4e6e29ae774ee0d1e
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised WordPress upload directories or disposable hosting, suggesting a link farm designed to redirect users. The presence of external URIs and the nature of the heuristics indicate the PDF's primary function is to lead users to malicious external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://crewmak.ru/uplcv?utm_term=ig+follow+apk PDF link annotation
    • https://nocenzura.space/web/img/podborky/files/1672330216.pdfIn PDF document text
    • http://kapelski.pl/userfiles/file/rimuwibogoriva.pdfIn PDF document text
    • https://securitydm.rs/slicice/file/48580010303.pdfIn PDF document text
    • http://modaxch.com/userfiles/files/3316681176.pdfIn PDF document text
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/732f0fc697458ec984f82cbe22cd8069/tixelew.pdfIn PDF document text
    • http://evaemlak.com/userfiles/file///fewilofuw.pdfIn PDF document text
    • http://alhambra.kopanramen.com/uploads/files/62475811812.pdfIn PDF document text
    • http://www.trisad.kz/ckfinder/userfiles/files/xoruganubuw.pdfIn PDF document text
    • http://szybkieprawko.pl/szybkieprawko.pl/user/admin/fck/file/79479970827.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16130dbfc24383---petegulevosimofajafinovo.pdfIn PDF document text
    • https://xehowo24h.com/images/ckeditor/files/42756058741.pdfIn PDF document text
    • http://4reality.cz/userfiles/files/baduxarikogufep.pdfIn PDF document text
    • https://elicopter-de-inchiriat.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1614ad6532e124---68477440237.pdfIn PDF document text
    • http://tongchangkj.com/uploadfile/file///2021092405513315.pdfIn PDF document text
    • https://mimpishiosatu.com/contents/files/91830036520.pdfIn PDF document text
    • https://egyiksem.hu/uploads/file/rogawadepezon.pdfIn PDF document text
    • https://ytdrive.com/CKEdit/upload/files/gafusogosogeratirefu.pdfIn PDF document text
    • http://songpinhao.com/userfiles/files/bakumowafilurixek.pdfIn PDF document text
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/161425d389d78a---30296186669.pdfIn PDF document text
    • http://taxfreepoint.com/file/xagelirifesukireva.pdfIn PDF document text
    • http://bienchidan.org/uploads/files/94981709935.pdfIn PDF document text
    • http://winfielddeli.com/ckfinder/userfiles/files/60712057926.pdfIn PDF document text
    • http://ibtaker.ps/userfiles/file/gatiligixakigomeg.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_off0000ad3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAD3F 15096 bytes
SHA-256: 7cbc13c8b8dada5482e7e25254d553856fcd3f633bdd83831b4f0ca6350dc829
font_01_sfnt_off0000d30c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD30C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000eb22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB22 9968 bytes
SHA-256: d734d8aeb5ebc9ec9e9814ba4e919d2049777104c1958c992137ca13911503ae