Malicious PDF — malware analysis report

Static analysis result for SHA-256 55c43b9d20dd0911…

MALICIOUS

PDF

76.6 KB Created: 2021-09-19 10:55:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: a3a23c5e636472b7527c11b7863ba029 SHA-1: 678015c7f601147817eb9e16d3a4ec6a9e75c83c SHA-256: 55c43b9d20dd091130f8423a8a5bfa697af6c567a4b11221625923d0794f81df
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised CMS upload directories, a common tactic for hosting malicious files. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of numerous links to PDFs on potentially compromised sites suggests a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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://brihat-group.com/assets/userfiles/files/fekubowimetorogedomul.pdf In PDF document text
    • https://kfk-dekoration.dk/images/uploadedimages/file/19533924828.pdfIn PDF document text
    • https://www.andimoda.com/wp-content/plugins/super-forms/uploads/php/files/18e81061ca0efe0a24a330e388242fb3/zazaja.pdfIn PDF document text
    • https://davidfoleyinc.com/userfiles/file/wegurovajusine.pdfIn PDF document text
    • http://ctkupavna.ru/upload/file/pateguzibepiwobizaza.pdfIn PDF document text
    • http://cofetariafraguta.ro/UserFiles/file/78725677671.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/1614558607e010---80360146294.pdfIn PDF document text
    • https://fiscconsulting.com/userfiles/file/17103869220.pdfIn PDF document text
    • http://agarimo.com/archivos/archivos/88625899216.pdfIn PDF document text
    • https://inprovitecuador.com/ckfinder/userfiles/files/17930071121.pdfIn PDF document text
    • https://hssanesteban.cl/files/lilovusagoxizifovopotuke.pdfIn PDF document text
    • http://stellar-toys.com/ckfinder/userfiles/files/64373630261.pdfIn PDF document text
    • http://arcstema.com/userfiles/files/balofodatipad.pdfIn PDF document text
    • http://israel-aliya.com/wp-content/plugins/super-forms/uploads/php/files/0ce4602cb4f38f2194435ed07595f429/futupexak.pdfIn PDF document text
    • http://aa-nusd.jp/2599390486.pdfIn PDF document text
    • http://sofia-es.tokyo/yamituki-n/uploads/files/31414861963.pdfIn PDF document text
    • https://hunghiephuylog.com/upload/files/velowobada.pdfIn PDF document text
    • https://hippodrome-compiegne.fr/www/uploads/file/2741243243.pdfIn PDF document text
    • https://alsultantrading.ae/userfiles/files/gisorugepurasom.pdfIn PDF document text
    • http://intproplaw.com/admin/uploads/file/tofilizovapebaj.pdfIn PDF document text
    • http://bafiti.com/sklep/userfiles/file/56494458496.pdfIn PDF document text
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/161355ecbf2cb0---tanabevum.pdfIn PDF document text
    • https://acp-luxusingatlanok.hu/ckfinder/userfiles/files/77828645247.pdfIn PDF document text
    • http://kleinschadenexperte.de/userfiles/file/fobifunilesola.pdfIn PDF document text
    • http://la-roofers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613bf11341279---994030380.pdfIn PDF document text
    • https://kaxtongroup.com/home5/maxconne/public_html/kaxtongroup/assets/images/newspostimages/files/miwope.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=yung+bratz+roblox+idPDF link annotation
    • 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_off0000c151.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC151 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d963.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD963 19760 bytes
SHA-256: 23123120c62a4c7b72c2bb30f2474a94e70e4f8bd738ffb4f0e19c0ede7bd5d2
font_02_sfnt_off00010cd1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CD1 10508 bytes
SHA-256: 84e819a54c42388b2f709b05ee34e168ded3d1139e9914d31345b096b060e492