Malicious PDF — malware analysis report

Static analysis result for SHA-256 25b6d92293dd3f58…

MALICIOUS

PDF

86.5 KB Created: 2021-07-12 22:32:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b4b598bf8c6228bf6702d587e737d6c2 SHA-1: 3be9e5437dd6da690a04e8275e60149b41ba3d5b SHA-256: 25b6d92293dd3f582f60dce74629732e38170c2483da68860d174410d09a6de1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The file functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites. These sites, in turn, host further PDF files, suggesting a multi-stage redirection or phishing scheme. The presence of external URIs and link farms on compromised CMS uploads points towards an attempt to obscure the ultimate malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

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://crewmak.ru/uplcv?utm_term=used+detach+lowboy+trailers+for+sale
    • https://pilotcenter.gr/wp-content/plugins/super-forms/uploads/php/files/t4v1jjp4tp6a85ucteo424c3lk/suzezugefavufaliwovalabi.pdf
    • http://minuspk.ru/minuspk.ru/userfiles/file/62381707199.pdf
    • https://hobbes-group.com/upload/files/1898406264.pdf
    • https://arizonalightingsales.com/wp-content/plugins/super-forms/uploads/php/files/5b1b63ceec31d4464d54347b3ef2877e/73732202636.pdf
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16071c980410bd---nerinijom.pdf
    • https://saraelv.no/wp-content/plugins/formcraft/file-upload/server/content/files/16098362ad0e4e---73936996498.pdf
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/160ab343b12591---jadetuk.pdf
    • https://advance-pack.com/editor_upload/file/wunolofutak.pdf
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a972141b3d3---86362092651.pdf
    • http://amon-syotengai.com/userfiles/file/wekagovesexoxenerulaza.pdf
    • http://studiotecnicoarduini.eu/userfiles/files/95021809531.pdf
    • http://allseasonsart.com/uploads/fck_uploads/file/65387486737.pdf
    • http://oreade-breche.fr/userfiles/file/11779593444.pdf
    • http://beergolfers.com./blog/images/file/42324454364.pdf
    • https://notofthisgalaxy.com/wp-content/plugins/super-forms/uploads/php/files/gnl9f3m2u78t97huj0p0tt45cf/35164208008.pdf
    • https://infravoip.com/wp-content/plugins/super-forms/uploads/php/files/d23ab8f6614a194b657dbf9d7a670e8a/33594711388.pdf
    • https://www.qbuildsoftware.com/wp-content/plugins/super-forms/uploads/php/files/4ec5f261a49941347dd3ee6c0fb847aa/12366590231.pdf
    • https://dallaslandscapedesign.com/media/files/memabezajuvitakevulu.pdf
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dd49b7fc55---lugetusix.pdf
    • https://youstore21.com/wp-content/plugins/super-forms/uploads/php/files/5ad954a4ef077eb13920f6a8fd3b0bce/81908981687.pdf
    • https://sipsib.ru/wp-content/plugins/super-forms/uploads/php/files/8ae014525c38315da966ad3c89144977/28627779974.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ec35.bin
797ac3144fc56eb53fa281638805fcac5f81e46622e8b0f62d5b6a7f7bfaf198
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC35 10816 bytes
font_01_sfnt_off0001055a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1055A 16792 bytes
font_02_sfnt_off00011d6c.bin
bdcf591d2b38b34e40c154b0a5e42c5cdbfbbfe218bd0510f50b1ae5ecb85549
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D6C 18004 bytes