Malicious PDF — malware analysis report

Static analysis result for SHA-256 28371e1d0c63e09a…

MALICIOUS

PDF

80.9 KB Created: 2021-09-14 04:52:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 46afbbeca6292ed32491c130a9af0099 SHA-1: 14e7a4efc3529b306e953799c137dba346117f58 SHA-256: 28371e1d0c63e09a0b9f54f0b021d8d31ec3fe01eee3eb139a70205d0b5fc826
156 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 a machine learning classifier and ClamAV, indicating a phishing or trojan threat. It contains numerous links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. No scripts were extracted, but the presence of external URIs and the overall structure strongly suggest the intent is to lure users to external, potentially harmful, websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://phoenixknights.co.uk/wp-content/plugins/super-forms/uploads/php/files/5a5ceb7121c07945a2b579ad98293e8c/60945743020.pdf In PDF document text
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/5254223995f97f8c2610c9625358aa8b/nirulutonilegevonezub.pdfIn PDF document text
    • http://malir-naterac.info/UserFiles/File/rimabuf.pdfIn PDF document text
    • https://xn--interpeas-r6a.es/upload/files/78741382211.pdfIn PDF document text
    • http://dreesmann-foto.de/userfiles/file/tomusox.pdfIn PDF document text
    • https://mondoaudio.it/img/uploaded/file/gonedowiromixonukogu.pdfIn PDF document text
    • http://toanthinh.vn/webroot/img/files/55331695707.pdfIn PDF document text
    • http://norilsk.torbay.ru/images/uploads/file/pufomedunotegagadar.pdfIn PDF document text
    • http://vet-arrighicolangelicristilli.eu/userfiles/files/gopitadovot.pdfIn PDF document text
    • https://mangalargalux.com.br/ckfinder/userfiles/files/befolewigebev.pdfIn PDF document text
    • http://ihdbd.org/upload/files/noruf.pdfIn PDF document text
    • http://www.jcca.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/1613d61cd71090---27285047801.pdfIn PDF document text
    • http://someteme.com/archivos/_20210908203226.pdfIn PDF document text
    • http://dreamscar.eu/userfiles/file/92328273492.pdfIn PDF document text
    • https://padservhosting.com/userfiles/file/mepususo.pdfIn PDF document text
    • http://reutlinger.pl/userfiles/file/22245014542.pdfIn PDF document text
    • http://regcureguide.com/files/files/sogifarirut.pdfIn PDF document text
    • https://marbletreasures.com/uploads/image/files/mafadojexutal.pdfIn PDF document text
    • http://www.greenfield-sustainability.com/images/files/zosomovolifuje.pdfIn PDF document text
    • https://heatingboiler.ca/fck_upload/file/30417232103.pdfIn PDF document text
    • http://ty-int.com/files/files/wezenunofiwomijasisik.pdfIn PDF document text
    • http://vetusmeter.com/images/upload/File/kosuzu.pdfIn PDF document text
    • http://novafish.it/userfiles/files/luxazikasexabonikaduf.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=suicide+squad+2016+onlinePDF 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_off0000d6aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6AA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eec1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEC1 10948 bytes
SHA-256: 12dcac39d7908536c472ab247acbf69a836415bcc847d49233b3a61b897f6386
font_02_sfnt_off0001080e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1080E 17904 bytes
SHA-256: 5772f20df89206b714b937eb012d25ac41e835dc31612633d5c66470221dee23