Malicious PDF — malware analysis report

Static analysis result for SHA-256 a81f5ce0e8fbdad8…

MALICIOUS

PDF

86.3 KB Created: 2021-09-09 13:02:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 3c9ee62647fe52a6b383ea2346560438 SHA-1: e6c549347f37ec9347b54b4d94d53ac74f7a9577 SHA-256: a81f5ce0e8fbdad8de12be91c566a40718113293b1232f0d59f9190662b17e1a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a link farm directing users to various external websites, some of which are hosted on compromised WordPress installations. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URLs suggest it's designed to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 https://coretry.ru/uplcv?utm_term=best+apps+for+sketching+on+android PDF link annotation
    • http://softwaretesting.kr/club/data/userfiles/file/20210908225456.pdfIn PDF document text
    • https://n95america.com/wp-content/plugins/super-forms/uploads/php/files/95d96d3cf3f0c02ed06cc16d6d0d0b37/vufaviwuk.pdfIn PDF document text
    • http://sosonomo.com/ckfinder/userfiles/files/73160643203.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/p4ngjp9rt2usk4ghppa6hd48vp/59351581836.pdfIn PDF document text
    • http://elcolono.net/userfiles/files/63635429714.pdfIn PDF document text
    • https://hkfew.org.hk/ckfinder/userfiles/files/revowomizifowawivaxave.pdfIn PDF document text
    • http://abwmarlboropike.com/uploads/files/dujuxazit.pdfIn PDF document text
    • https://dalycity.com/wysiwygfiles/file/zusexekagodusuw.pdfIn PDF document text
    • http://bennett-legal.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/54606121554.pdfIn PDF document text
    • http://ambvetfanini.eu/userfiles/files/woviredibobare.pdfIn PDF document text
    • http://palmdale.thepokeluau.com/uploads/files/nazojimif.pdfIn PDF document text
    • http://bioaec.com/userfiles/files/7042721478.pdfIn PDF document text
    • http://seoulsquare.com/userfiles/file/pigiv.pdfIn PDF document text
    • http://www.webtony.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16134a8468d60a---vemavetigugaroxeguti.pdfIn PDF document text
    • https://stmpallet.com/ckfinder/userfiles/files/34094343455.pdfIn PDF document text
    • http://farashimirooz.com/files/sijelajojarokawomilipiw.pdfIn PDF document text
    • http://lutechmed.com/Images_upload/files/86095863976.pdfIn PDF document text
    • http://twgo8.com/uploads/base/files/202109022001006547.pdfIn PDF document text
    • http://curvesncontours.com/userfiles/file/tafixudefazul.pdfIn PDF document text
    • https://amadesafar.ir/basefile/amadesafarir/files/32894403477.pdfIn PDF document text
    • https://getlovebooks.com/wp-content/plugins/super-forms/uploads/php/files/0b7902d63c1d0b10a8bb84d577bdae6d/mesapemaneduwi.pdfIn PDF document text
    • http://stphilomenaonline.org/userfiles/file/66778285555.pdfIn PDF document text
    • http://fgsconsulta.com.br/ckfinder/uploads/userfiles/files/lupurapapebetidese.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_off0000ed09.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED09 17360 bytes
SHA-256: ba244e3c717c9b8eb0d531d6d5203631067a508faa9d5ce420aa1bfcf453dcf7
font_01_sfnt_off0001198e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1198E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000131a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x131A5 11000 bytes
SHA-256: 902e1e4d769568c015cc2966cd0dbef37176a6352cd7b26f57c3ca53acfa0da1