Malicious PDF — malware analysis report

Static analysis result for SHA-256 caa5a071986814a4…

MALICIOUS

PDF

74.2 KB Created: 2021-09-14 10:04:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 17a2f110858f909b5669681296f85c70 SHA-1: 49d2644d961385061e3b6b76c5b01b99ad51b4fd SHA-256: caa5a071986814a49f460a8ebe6e502870563486d67b5eca6ce317e77665bd94
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to multiple domains, many of which appear to be compromised WordPress sites. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM indicates a pattern of using disposable hosting for these links. While no scripts were directly extracted, the ML classifier strongly suggests malicious intent, likely to redirect users to download unwanted or malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • 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://regenerativetherapyforpain.com/wp-content/plugins/super-forms/uploads/php/files/89defa77b01c4648417552cb28bd4452/fiwebisapozukema.pdf In PDF document text
    • https://efficimm.fr/userfiles/files/70485970877.pdfIn PDF document text
    • http://micruts.org/userfiles/file/katol.pdfIn PDF document text
    • http://birkhoffhi.com/userfiles/files/fasobexenujazo.pdfIn PDF document text
    • https://emailing-online.fr/uploads/userfiles/file/zodiweteposivusorizesenob.pdfIn PDF document text
    • https://bustotoronto.com/userfiles/file/13048453809.pdfIn PDF document text
    • http://bresky.cz/res/file/zabogu.pdfIn PDF document text
    • https://www.pfgpartners.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161403c5ea824e---87192653814.pdfIn PDF document text
    • http://vasilii-orlov.fun/wp-content/plugins/super-forms/uploads/php/files/9a377ae5b8ef09dc96f198b77266c5e3/3180699547.pdfIn PDF document text
    • http://smolninskayahotel.com/userfiles/file/begejovejozopazig.pdfIn PDF document text
    • http://promtour-rural.ro/userfiles/file/61562166896.pdfIn PDF document text
    • http://mcenterdk.ru/fck_editor_files/files/6039430265.pdfIn PDF document text
    • https://cncunse.com/d/files/47895928708.pdfIn PDF document text
    • http://munsusa.org/userfiles/file/20210912054936.pdfIn PDF document text
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/16134cf93903b1---nepirejorigudowizetazor.pdfIn PDF document text
    • http://af.ssla.ru/images/fornews/files/konodigibu.pdfIn PDF document text
    • https://marblobaths.com/app/webroot/img/files/30634702120.pdfIn PDF document text
    • http://contactfm.be/userfiles/files/notikividugano.pdfIn PDF document text
    • http://le-nora.com/userfiles/file/tifukarirusef.pdfIn PDF document text
    • https://booking-news.hkdnracing.com/webroot/editor-uploads/files/14606396748.pdfIn PDF document text
    • https://www.cukoyem.com.tr/wp-content/plugins/super-forms/uploads/php/files/gn3strtc7clg4gig3oviftkbg0/fixubukoz.pdfIn PDF document text
    • http://sobinco.cz/ckfinder/userfiles/files/katavenifeme.pdfIn PDF document text
    • http://inggeo.eu/userfiles/files/vinifixisosolemifof.pdfIn PDF document text
    • http://hndgyl.com/v15/Upload/file/20219306144050.pdfIn PDF document text
    • http://tsrmvolontari.it/userfiles/files/18696314062.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=download+gacha+mod+apkPDF 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_off0000be8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE8F 17228 bytes
SHA-256: 038ce8b8924b39f8e37f5aa1b359525d0816e328e9fbfbef3e9ddaaf27638b1b
font_01_sfnt_off0000eb3c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB3C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010353.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10353 10548 bytes
SHA-256: 125070d158787ea0a803b0b52185c0586d61464e3d8ba9ef6430998e06de2525