Malicious PDF — malware analysis report

Static analysis result for SHA-256 b573769931c57cee…

MALICIOUS

PDF

81.7 KB Created: 2021-09-09 01:47:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 4125d7b4acbf9f3154cb1300552831e3 SHA-1: 566746f5eead83c15fe57ad939992688bffbc840 SHA-256: b573769931c57cee68a58eeab204b05b2062b289b4583d13b093c07f931f9692
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1553.005 Mark-of-the-Web Bypass

This PDF was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier indicating maliciousness. The presence of a 'Security software disable instruction' heuristic strongly suggests an attempt to bypass defenses. While no scripts were extracted, the document's structure and embedded URLs point towards a phishing or malware delivery attempt, likely initiated via a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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
  • Security software disable instruction high SE_SECURITY_BYPASS
    Document instructs the user to disable antivirus or security software — unusual for ordinary documents and high-risk in an unsolicited file
  • 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://bandotrading.it/uploads/file/14658079041.pdf In PDF document text
    • https://deniz-sogutma.org/img/userfiles/file/88978938963.pdfIn PDF document text
    • http://forter.vn/hinhanh/file/16409946587.pdfIn PDF document text
    • http://ampletrekking.com/userfiles/file/945798241.pdfIn PDF document text
    • http://dellalontra.it/userfiles/files/489755003.pdfIn PDF document text
    • http://fermobkorea.com/userfiles/file/20210909055148.pdfIn PDF document text
    • https://pastelbuilders.com/userfiles/file/48115594209.pdfIn PDF document text
    • https://bodymason.com/user_uploads/files/puvekudijekerovafanobute.pdfIn PDF document text
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613562eb058cf---napexupuzage.pdfIn PDF document text
    • http://msiutilities.biz/documents/3922264294.pdfIn PDF document text
    • http://www.aceitunasdelguadalhorce.es/ckfinder/userfiles/files/guzuru.pdfIn PDF document text
    • http://cementfeet.com/userfiles/file/dojopugaranowasugoj.pdfIn PDF document text
    • http://markone-tools.com/upload/files/vimumug.pdfIn PDF document text
    • http://chamdure.com/DATA/files/rarelaminuxuxalukejufepi.pdfIn PDF document text
    • http://evergladesharvesting.com/ckfinder/userfiles/files/29919568569.pdfIn PDF document text
    • https://defi128.phpascal.com/userfiles/files/2011320309.pdfIn PDF document text
    • http://nataliashishkina.com/userfiles/file/tuzata.pdfIn PDF document text
    • http://yidaig.com/uploadfile/file/20210907051121.pdfIn PDF document text
    • https://ventsistem-bg.com/userfiles/file/fenenopupenizokunifisa.pdfIn PDF document text
    • https://sieuviet.net/webroot/img/files/44176677653.pdfIn PDF document text
    • http://massvt.sk/editor_uploads/system/files/86429530949.pdfIn PDF document text
    • http://eternaseguros.net/files/files/40775357709.pdfIn PDF document text
    • http://zentrumok.com/userfile/files/55058446829.pdfIn PDF document text
    • https://montpellier-business-plan.com/mbp/upload/images/images/upload/ckfinder/gisorujetedikigajozaviwok.pdfIn PDF document text
    • http://cmi.nfe.go.th/ckfinder/userfiles/files/logan.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=how+to+lock+messenger+app+on+androidPDF 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://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_off0000daf3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAF3 17084 bytes
SHA-256: 6c33931c0786c7cdea0d5d9d6d7bb24b27ba53cf77a2bcc1eb0c10b4c9d601dc
font_01_sfnt_off0001070d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1070D 11024 bytes
SHA-256: e304a0200746fbe9e2832eeecbbb2639c4a8e38608fbd2a6d573cfc6afaa75f9
font_02_sfnt_off0001207b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1207B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1