Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4a3fcc153a3d061…

MALICIOUS

PDF

88.3 KB Created: 2021-09-06 22:35:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: cabfa24ac0f6894c4bc59e26d20a1283 SHA-1: 3567f5f256cd9ace604f03bd5f596b0842fcafb2 SHA-256: b4a3fcc153a3d0614b51adff3ea982d314ea5080c3a4613cbeeb538b629ba993
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristic analysis revealed it functions as a link farm, containing numerous URLs pointing to compromised CMS uploads and disposable hosting. These links likely serve as a lure to redirect users to phishing or malware distribution sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://clinicacomciencia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160d96358df310---61763575492.pdf In PDF document text
    • http://accessibilite-salle-eau.com/ckfinder/userfiles/files/9447598385.pdfIn PDF document text
    • http://richwoods1969.com/clients/861079/File/tomepiteturuvitawalepiw.pdfIn PDF document text
    • http://funperm.ru/content/file/kafovelasugewoviz.pdfIn PDF document text
    • http://biomassasia.net/data_ed/userfiles/file/89087089424.pdfIn PDF document text
    • https://oxi-dental.ro/imagini_ws/24149711223.pdfIn PDF document text
    • https://ssvacancy.com/ckfinder/userfiles/files/depomi.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bdd511a4f69---kevijarutug.pdfIn PDF document text
    • http://leinerpakgelatine.com/survey/userfiles/files/nalajazibefe.pdfIn PDF document text
    • http://cuatro-pr.org/sites/default/files/file/87800519243.pdfIn PDF document text
    • https://tiklatakip.com/calisma2/files/uploads/wokobevomikej.pdfIn PDF document text
    • http://africansafaris-spain.com/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/fimati.pdfIn PDF document text
    • https://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/99c59f563ef0ed5809ff0738a7461d38/dikoremet.pdfIn PDF document text
    • http://tanriovermensucat.com/uploads/genel/files/10976615336.pdfIn PDF document text
    • https://rclurie.com/wp-content/plugins/super-forms/uploads/php/files/90fe538453d3a00dbb260a51b7beeaf9/68299970559.pdfIn PDF document text
    • http://brenderup.ro/mm/file/semezolefikunamojoxutelof.pdfIn PDF document text
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/qs45kc0ve1h3rt10i9f0nh4glc/96050645597.pdfIn PDF document text
    • http://familiegravesen.dk/userfiles/file/18335906781.pdfIn PDF document text
    • http://bluecreator.biz/ckfinder/userfiles/files/mibokupuxivezoliwepar.pdfIn PDF document text
    • http://emannsltd.com/userfiles/93469214938.pdfIn PDF document text
    • https://ensasoft.com.tr/wp-content/plugins/super-forms/uploads/php/files/ssju120s5p29g8e3tsi8127urt/9730377562.pdfIn PDF document text
    • http://first-group.kr/ckupload/files/luviniwijamofagavoxol.pdfIn PDF document text
    • http://yakutiaprime.ru/SITE/files/editor/file/98689902148.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=l%27agriculture+et+le+d%C3%A9veloppement+durable+pdfPDF 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_off0000eb37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB37 20620 bytes
SHA-256: dcca9b97fdec07747a443d0de3d2fb418967fc171c7b488f2f149660d899d934
font_01_sfnt_off00011f98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F98 11248 bytes
SHA-256: 5960e3101c9312071ce79ceda064b514500ad58c056425bd4680992fb4edded7
font_02_sfnt_off00013944.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13944 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1