Malicious PDF — malware analysis report

Static analysis result for SHA-256 35b87689a69a56c4…

MALICIOUS

PDF

74.6 KB Created: 2021-09-17 16:17:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 6c3dbcd0665c2ce43c76a7bbf1020859 SHA-1: b995f6c476f18869dcf2b6797e280e196032528a SHA-256: 35b87689a69a56c46f4387ecafb74ff6f8f9bc2cc2a9674a50b896970731887b
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by multiple heuristics as malicious, including ClamAV detection and an ML classifier. It contains numerous embedded URLs pointing to various domains, many of which appear to be compromised WordPress sites or disposable hosting. These URLs are likely used to distribute further malicious content or conduct phishing attacks. The presence of a link farm and the use of UTM parameters suggest an attempt to track user engagement with malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://pistant.ru/uplcv?utm_term=olx+android+app+free+download PDF link annotation
    • https://bdblue.com/ckfinder/userfiles/files/vizupesepotamofupivew.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/1613f9d9b6c9b7---zizalalebitoxuxibipavonol.pdfIn PDF document text
    • http://newgrids.com/userfiles/file/kejilemebujedov.pdfIn PDF document text
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/8b9006d4a004704aeaf136af9eabf29f/8434534287.pdfIn PDF document text
    • https://sweetestspaparty.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131551655209---laniluzozuxajevatata.pdfIn PDF document text
    • https://highlander-inn.com/assets/userfiles/files/takamameziregufituga.pdfIn PDF document text
    • http://benardoutlite.com/admin/fckeditor/fckdata/file/79818550343.pdfIn PDF document text
    • http://www.santabriganti.org/admin/ckfinder/userfiles/files/64504941011.pdfIn PDF document text
    • https://www.bevillelecomte.com/ckfinder/userfiles/files/zelizidibibuvexowetub.pdfIn PDF document text
    • http://internationalnetworksolutions.net/files/In PDF document text
    • http://webinaris.net/ckfinder/userfiles/publics/files/59091443618.pdfIn PDF document text
    • http://tonghuichem.com/upload/files/84979168039.pdfIn PDF document text
    • http://178.62.148.222:300/ckeditor/ckfinder/userfiles/files/33752882697.pdfPDF link annotation
    • https://newfrio.com/userfiles/files/10226181818.pdfIn PDF document text
    • http://showpalmedical.com/userfiles/tejikafobijo.pdfIn PDF document text
    • https://aldwalia.com/userfiles/files/18298259664.pdfIn PDF document text
    • https://www.cascatai.com.br/ckfinder/userfiles/files/rujesowasolukex.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161403496af364---95133189679.pdfIn PDF document text
    • http://nhatrangpalace.vn/app/webroot/upload/files/77753054079.pdfIn PDF document text
    • http://interroadholland.nl/userfiles/file/12773002589.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/1613cb3f6884bd---nidexodopeditogive.pdfIn PDF document text
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136c89d6174b---josizolukufovamavagomepam.pdfIn PDF document text
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/161441e892576d---8882115198.pdfIn PDF document text
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138e8fe79dc9---86594400688.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://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_off0000c53e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC53E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dd50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD50 17580 bytes
SHA-256: 89120847d8f564ddfa495c0597468664b91af9db902fd0afa5d86461a0960817
font_02_sfnt_off00010b03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B03 10436 bytes
SHA-256: a32971da8542cbe03bffa004d92b06c786bcca3d5767dc756abe755e455f44e1