Malicious PDF — malware analysis report

Static analysis result for SHA-256 671d278cf212d598…

MALICIOUS

PDF

72.7 KB Created: 2021-09-26 04:52:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: f4775fc812dba993703341b547766393 SHA-1: 298c1d67c728ec34dd3fbbc208ceb6b8acc49959 SHA-256: 671d278cf212d5985b9659be17ea9208d210284a7a831dde72221174bc012dd9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to various domains, many of which are hosted on compromised CMS platforms or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to deliver second-stage payloads or redirect to phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://medvor.ru/uplcv?utm_term=como+desbloqueo+mi+android+samsung PDF link annotation
    • http://sirmamedia.com/ckfinder/userfiles/files/mamefutiwiruganebatixik.pdfIn PDF document text
    • http://baove24h.org/upload/files/senexigi.pdfIn PDF document text
    • http://kutyasturak.hu/images/files/nuginofabobal.pdfIn PDF document text
    • http://www.ponderosafestival.com/wp-content/plugins/formcraft/file-upload/server/content/files/16148f6dc014b7---29218750521.pdfIn PDF document text
    • https://oilbasaro.com/web/images/ckfinder/files/20210914112146.pdfIn PDF document text
    • http://bloomx.com/sites/all/sites/bloomx.com/files/43462998679.pdfIn PDF document text
    • http://kondicionery-krasnogorsk.ru/upload_picture/file/99728067689.pdfIn PDF document text
    • http://mexxeopaint.com/upload/files/25974958498.pdfIn PDF document text
    • http://sotel-perm.ru/site/file/84458477920.pdfIn PDF document text
    • http://romanasulcikova.cz/userfiles/faximakikimuj.pdfIn PDF document text
    • http://novena99.com/uploads/files/202109170831435333.pdfIn PDF document text
    • http://swaving-stalinrichting.nl/ckfinder/userfiles/files/23592492958.pdfIn PDF document text
    • http://thanhlapcongtykiengiang.com/upload/ck/files/diker.pdfIn PDF document text
    • http://vietkinggroup.com/uploads/userfiles/file/nedazimaladitugot.pdfIn PDF document text
    • http://pocatellocampfire.com/wp-content/plugins/super-forms/uploads/php/files/va3m046t2p71pk64ukgkqqaloh/38292396859.pdfIn PDF document text
    • https://www.area-tlc.com/public/ckfinder/userfiles/files/fefutelobokopon.pdfIn PDF document text
    • http://em-mould.com/ckfinder/userfiles/files/kanobaborezowivasasefu.pdfIn PDF document text
    • http://trenermichal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16148a589e8543---kalezum.pdfIn PDF document text
    • https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d3193303a3---47359825564.pdfIn PDF document text
    • https://cooperadora.grupocreartel.com/documentos/archivos/nalafev.pdfIn PDF document text
    • https://www.digitalsofts.com/wp-content/plugins/formcraft/file-upload/server/content/files/161435687739b3---xugonedofulojitorapal.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_off0000b890.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB890 17036 bytes
SHA-256: c410bf155d7e313505ac92e8b8c329e080f227f2e2ac1c5f1407c476a93fef87
font_01_sfnt_off0000e478.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE478 10908 bytes
SHA-256: 250878dcba07f39b5186b0d5975ebf9091ff5feffb6087b9bd346b793e8f18aa
font_02_sfnt_off0000fd1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD1C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1