Malicious PDF — malware analysis report

Static analysis result for SHA-256 97a78b3f5209f2be…

MALICIOUS

PDF

80.0 KB Created: 2021-09-17 05:10:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ecaa44a4c43e3a2f3e4f792c15797af3 SHA-1: 670f3af63077d640062d2290359a8fb564ce9e13 SHA-256: 97a78b3f5209f2bed122d1707e254111c2172a247d17acbfe93b7e593a7e0e83
164 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to various domains, many of which appear to be part of link farms or compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious content. The presence of a 'download button' heuristic further supports the interpretation that the document is designed to trick users into downloading a payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://krisoc.ru/uplcv?utm_term=discovery+computer+book+2018+pdf
    • http://paradisoseminatrici.it/userfiles/files/zugesegev.pdf
    • http://cuacuonnhanh.vn/Images_upload/files/31275539113.pdf
    • http://njboyuanchem.com/upload/files/96270875232.pdf
    • http://villaturri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b4fb415ee5---demuxerisemofonojofox.pdf
    • http://www.sloepverhuur-debiesbosch.nl/upload/files/66691181387.pdf
    • https://prestinireedcorp.com/userfiles/files/25652997457.pdf
    • http://soles2walk.cz/data/file/jipusu.pdf
    • http://dfwsedan.com/nbloom/fckuploads/file/kulinuva.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fb94912e5e---kidezumojafotamawikod.pdf
    • http://xmzhj.com/UserFiles/file/18235920046.pdf
    • http://accronline.com/userfiles/file/noditilamutowomu.pdf
    • https://clinicscrm.com/img/files/lamimelotajubuz.pdf
    • https://www.sidertest.it/wp-content/plugins/formcraft/file-upload/server/content/files/1612ed279d919d---dubusebinogumekunom.pdf
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135f562b94e7---74109900932.pdf
    • https://cncunse.com/d/files/69623118647.pdf
    • http://cansuyu.org/resimler/files/tuwabaxemufo.pdf
    • https://hoangvan.vn/wp-content/uploads/files/90929009867.pdf
    • http://proartgaleria.hu/files/files/tezevonebajenujolot.pdf
    • http://brette-animation.com/userfiles/file/kudilupaxopejotesab.pdf
    • https://kingyao.com/uploadfiles/files/20210906_202236_9266.pdf
    • http://freeski.hu/freeski/file/58950087264.pdf
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/16135ab9e50630---78432684974.pdf
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613912c6d4745---35329273403.pdf
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/16134453479c11---90651470898.pdf
    • http://onlinetalk.jp/app/webroot/img/fckfiles/file/fofozigejolirageganebu.pdf
    • http://www.stallionreadymix.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16137d2102d74a---zituzidopifeta.pdf
    • https://clinicaabrahaoosta.com.br/ckfinder/userfiles/files/dekuxo.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_off0000d3bb.bin
d21295437779637e415aa5a13290711e452ced79bddb2f2c73b57076cf3f9f30
pdf-font-stream PDF embedded font (sfnt) at offset 0xD3BB 16752 bytes
font_01_sfnt_off0000ff32.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFF32 16792 bytes
font_02_sfnt_off00011749.bin
f3c70f29ef1dd0f527868be6786afa8bdc0f43e2dbf9944e9a1cf6dcf0277704
pdf-font-stream PDF embedded font (sfnt) at offset 0x11749 11484 bytes