Malicious PDF — malware analysis report

Static analysis result for SHA-256 537c5940020061ba…

MALICIOUS

PDF

70.1 KB Created: 2021-09-24 21:50:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: b100a41e9e0a94f26b8500853fecc8c9 SHA-1: 84f71893e9c9c33fd801251c8e5a6505ba15cf2e SHA-256: 537c5940020061ba55e51a7de0b72b29ceee55d5cd21a44a06645ad6f3739653
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a significant number of external URIs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed for malicious distribution. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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 http://ttccid.com/userfiles/files/2861458374.pdf In PDF document text
    • https://obermeyer-modemarkt.de/upload/file/93315936666.pdfIn PDF document text
    • https://aokman-drive.com/d/files/tidonajipide.pdfIn PDF document text
    • http://sghr.ca/upload/ckfinder/files/68620013044.pdfIn PDF document text
    • https://voicelux.ru/wp-content/plugins/super-forms/uploads/php/files/d1aa3dde735703231a285b645e427e33/vidowuku.pdfIn PDF document text
    • https://silverlabpupsforsale.com/userfiles/files/vezukinikima.pdfIn PDF document text
    • http://sacoorhealth.pt/site/upload/file/tonowutalilaporegode.pdfIn PDF document text
    • https://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/m5m7e7iv3skmki1rouef3qlijj/xupazew.pdfIn PDF document text
    • https://autopsrus.com/ckfinder/userfiles/files/20545756941.pdfIn PDF document text
    • http://hourinkan.net/js/upload/files/jobaworaxexuduka.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613489c2cb594---rolamop.pdfIn PDF document text
    • http://karaokejdi.com/ckfinder/core/connector/php/upload/files/rilusor.pdfIn PDF document text
    • https://textosolutionslinguistiques.ca/upload/editor/file/51935276404.pdfIn PDF document text
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/161337ed5b7714---tibegepujujupisurenusimad.pdfIn PDF document text
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/cf71d5ba0b758a6f2ecaccd517bc23b3/86236288220.pdfIn PDF document text
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/c00cb79bd46db756900d75c1346938c3/15112836800.pdfIn PDF document text
    • http://foto-recepty.sk/images/fotky/vefumibe.pdfIn PDF document text
    • https://egyiksem.hu/uploads/file/49736945962.pdfIn PDF document text
    • http://vo23.ru/upload/file/89258440542.pdfIn PDF document text
    • http://kasintorn.com/images/upload/files/5465781697.pdfIn PDF document text
    • http://iucecb.com/files/file/66724445898.pdfIn PDF document text
    • http://scandinavia-ex.com/images/blog/file/48634430836.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=hide+floating+action+buttonPDF 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_off0000b20e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB20E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ca20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA20 15888 bytes
SHA-256: b93a15df7489ce641a7568189cea1b49aed34734840b9e0ec474d199fa970c8e
font_02_sfnt_off0000f2d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2D0 10616 bytes
SHA-256: 15902acb54e5405d8f8df3398547025e9adbc46d97d2d01acd2d5d71c27b58ab