Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb31db1eff5b1c7f…

MALICIOUS

PDF

79.9 KB Created: 2021-09-01 12:13:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: f02e6fcb55fd689fab91af48f2a2469a SHA-1: c4eed266aef57bb8836a760a2538150f1e16b80e SHA-256: cb31db1eff5b1c7f36aedd70b1d25fcf00e4e0233b4680e7f8ea87b3e6c8cd0e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The document contains numerous links pointing to external websites, many of which are hosted on compromised WordPress sites or disposable domains, suggesting a link farm designed to redirect users to malicious content. The presence of embedded URLs and the overall structure indicate an attempt to facilitate phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9944

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://inwebjor.ru/uplcv?utm_term=marvel+contest+of+champions+crystal PDF link annotation
    • http://cintabogor.com/Uploads/userfiles/files/tesaxowemaneru.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/16121d05acdde9---rodorugivunesoraf.pdfIn PDF document text
    • https://sipsib.ru/wp-content/plugins/super-forms/uploads/php/files/c27d50c9e8c65094728aba1195a36ba6/xuwosuzenovazironela.pdfIn PDF document text
    • http://kristiankutschera.de/userfiles/file/lujelagimurijezu.pdfIn PDF document text
    • http://herfon-machinery.com/images/ckfinder/files/20210814100321.pdfIn PDF document text
    • http://aldo-ins.com/userfiles/file/zajozo.pdfIn PDF document text
    • http://shqinze.net/admin/upimg/file///kibulavotolopusibufogunut.pdfIn PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/mnoh7fsjhh6pjso1fhc003rea4/kijopuri.pdfIn PDF document text
    • https://noithatkuongthinh.com/uploads/files/rirudupigowitolojalarinow.pdfIn PDF document text
    • http://weilandensemble.nl/ckfinder/userfiles/files/19883944685.pdfIn PDF document text
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a49b186cb0f---67483283720.pdfIn PDF document text
    • http://nitexprofi.cz/userfiles/file/62816575342.pdfIn PDF document text
    • http://ibshop.gr/uploads/_uploads/files/18389714754.pdfIn PDF document text
    • http://enerjipiyasalarizirvesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c75bd81f4a---tumeditowoka.pdfIn PDF document text
    • http://venusland.vn/app/webroot/img/files/49832414821.pdfIn PDF document text
    • http://elma1.ru/!upload/files/2427307501.pdfIn PDF document text
    • https://makanbanyak.net/contents//files/valusovulajevonazivubo.pdfIn PDF document text
    • http://mgtofubbq.com/uploads/files/31999737528.pdfIn PDF document text
    • http://royalgoodviewresort.com/Uploads/file/fefiragemij.pdfIn PDF document text
    • http://xn--42-6kcdlkbomh7beggito5p.xn--p1ai/userfiles/file/likuwuvap.pdfIn PDF document text
    • http://www.pzkexie.com/up_files/file/1501977882.pdfIn PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/kfj6bcvj6a2u1o3m97qambios8/97646705688.pdfIn PDF document text
    • https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cc29a78cf9e---guzobarelasu.pdfIn PDF document text
    • http://suarezbeltran.com/aym_images/files/xobafikunobodububugokavap.pdfIn PDF document text
    • https://www.taxikladis.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160761bb534cd9---6797853223.pdfIn PDF document text
    • https://priscar.com/documents/files/91002546415.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_off0000d41e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD41E 16924 bytes
SHA-256: 2b998ef22385a5a76f1659aadbcc937af69cea1bae021c7758270aa3d082f72a
font_01_sfnt_off0000fff0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFF0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011807.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11807 10916 bytes
SHA-256: deff0331bc17e4b68c4ad03543ee5367337472e9dd7a76d7e8f6c308f48193d3