Malicious PDF — malware analysis report

Static analysis result for SHA-256 900246b5f0ee6065…

MALICIOUS

PDF

69.2 KB Created: 2021-09-24 17:33:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: a9a9faa3a3b4afee78d9ffba007a8709 SHA-1: e97e55828e480c62f3451565d571e1f2940d4a5d SHA-256: 900246b5f0ee6065f468062277ebb3fbd8e9a82a80799a744f1bba9814012c7c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to PDF files hosted on various domains, indicating a link farm designed to redirect users. Heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' suggest these links are part of a scheme to distribute malicious content or phish for information. The ML classifier and ClamAV detection further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://smidgel.ru/uplcv?utm_term=pes+2019+app PDF link annotation
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1614c60e73fd81---duliziwezovanuw.pdfIn PDF document text
    • http://hgbs.de/userfiles/file/vekesoxedenuwufefuvovofel.pdfIn PDF document text
    • http://pekbdt.com/filespath/files/20210913193517.pdfIn PDF document text
    • http://baggiez.net/userfiles/file/puranaviwu.pdfIn PDF document text
    • http://georgekoldun.com/var/upload/file/gunutazefepi.pdfIn PDF document text
    • http://tongrentangthai.com/UserFiles/file/tojimanaredixogiperulabif.pdfIn PDF document text
    • http://webmenuplus.com/images/file/29622518326.pdfIn PDF document text
    • https://easresidence.ro/app/webroot/files/userfiles/files/54151125959.pdfIn PDF document text
    • https://servingltda.com/userfiles/file/fefexuje.pdfIn PDF document text
    • http://www.smartlandgroup.com/ckfinder/userfiles/files/71999661337.pdfIn PDF document text
    • http://lso-msm.com/userfiles/file/73577776574.pdfIn PDF document text
    • https://rougezenekar.hu/files/file/dakusakifafudefejula.pdfIn PDF document text
    • http://vanillasky-ch.com/images/files/65430948361.pdfIn PDF document text
    • http://wangguanhardware.com/userfiles/file/lorepojer.pdfIn PDF document text
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/gkav9oeevc1itu7n81vrk9lhrq/40482551809.pdfIn PDF document text
    • http://nhadephoanhao.vn/upload/ckupload/files/61692486494.pdfIn PDF document text
    • http://imhyuk.com/imhyukeditor/userfile/file/napodexobowikifa.pdfIn PDF document text
    • https://fleseriuassociates.ro/files/file/52320273290.pdfIn PDF document text
    • http://chiesamadremarsala.eu/userfiles/files/11283528477.pdfIn PDF document text
    • http://debandhelder.nl/ckfinder/userfiles/files/34083580984.pdfIn PDF document text
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161487a6fc321e---29829093888.pdfIn PDF document text
    • http://eatatrudy.com/uploads/files/53055148669.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_off0000ae5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE5F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c676.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC676 10148 bytes
SHA-256: 5521f27a8a76d9bf3c33a0715d277dc64702ef83d8ce971cf036e3c1ce74e959
font_02_sfnt_off0000dd66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD66 16720 bytes
SHA-256: f8dde5f50aafe2ab14850e670514d601a25d9df550152db1f38249449e467edb