Malicious PDF — malware analysis report

Static analysis result for SHA-256 f0bfe7885be49985…

MALICIOUS

PDF

75.5 KB Created: 2021-06-12 14:22:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: 32bf6081b7d33e68fabf311b75c83c90 SHA-1: ff0c991d9b18a3cc8502472df2a2d407a8abc617 SHA-256: f0bfe7885be49985c61f37d1b333666629fd8f0dc433744f5f6815b01319d569
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains numerous links to compromised websites, many of which are hosted on WordPress installations and appear to be part of a link farm. The document body, though heavily obfuscated, suggests a lure related to 'inverse variation worksheet answers'. The presence of multiple external URIs and the ML classifier's high confidence score indicate a malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the heuristic firings strongly suggest a link-based attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://pixomot.ru/uplcv?utm_term=inverse+variation+worksheet+answers PDF link annotation
    • https://outsourcedbackoffice.co.uk/wp-content/plugins/super-forms/uploads/php/files/46fd22fc9387730341b5b54a0cdd9558/jetasagujelubu.pdfIn PDF document text
    • https://fastcomputer.vn/wp-content/plugins/super-forms/uploads/php/files/b7d7a7459846f531fa8e5da8d040a378/58874361255.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/3cq2vmehj2miklgiot70op58e5/lurazawut.pdfIn PDF document text
    • http://ophirtonhotel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1606e8834cb671---pimikele.pdfIn PDF document text
    • https://penzionradvanice.cz/res/file/28193938860.pdfIn PDF document text
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6bc9dd4318---xukisufavogiposuruzuzixin.pdfIn PDF document text
    • http://call.ae/wp-content/plugins/formcraft/file-upload/server/content/files/1608a93e6b60eb---kademonukozezusuvudo.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/ce1jpcsq4tekae7rtfaj4tan0i/85319337955.pdfIn PDF document text
    • http://greenplanetnepal.com/userfiles/file/gatafeluvaru.pdfIn PDF document text
    • http://shinserviceodi.ru/wp-content/plugins/super-forms/uploads/php/files/5b9a327597a486c9e0ba39078bce3ccf/gefulubapid.pdfIn PDF document text
    • https://www.tonygssoulfood.com/wp-content/plugins/super-forms/uploads/php/files/423b1339324d628a453096e7a2f870f0/25704713302.pdfIn PDF document text
    • http://sakaryakasaplarodasi.org/userfiles/file/41303322321.pdfIn PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607175f2b8bdf---20541869367.pdfIn PDF document text
    • http://stylist.in.ua/wp-content/plugins/formcraft/file-upload/server/content/files/160b80e137c32a---9486261611.pdfIn PDF document text
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160b866a6e219f---gopululojopulemo.pdfIn PDF document text
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/43447eeadd3f51532ce8a0bff2de6aa5/37428251798.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ec76b96242---59250486432.pdfIn PDF document text
    • https://givemeit.ru/wp-content/plugins/super-forms/uploads/php/files/2d39dfbc141e97f8829bd4bf25a3adf1/labasofofuk.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ecb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECB3 4892 bytes
SHA-256: 054be93699df308c062e670c85ac900ff9fbf3f582566cb3fbf2433e9ec94950
font_01_sfnt_off0000fd6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD6A 10384 bytes
SHA-256: 2a1bbfcc63a3db30ec73fdce96a952f52e4fbb338bb47b8a5a14eebe655dcd39