Malicious PDF — malware analysis report

Static analysis result for SHA-256 44553372a35c54d6…

MALICIOUS

PDF

77.0 KB Created: 2021-09-13 15:27:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 56cec3a84a0614ec5086d44a6b96a273 SHA-1: 16639d13769405a11d9799ecabfeda0eb54c35fc SHA-256: 44553372a35c54d6deee5a5ffcfbd2dfc3ef520e463338242f7a02a3851ab418
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains a link farm with numerous URLs pointing to other PDFs, a common tactic to obscure malicious intent and potentially bypass gateway scanning. The heuristic 'SE_PASSWORD_ARCHIVE_LURE' indicates the document likely instructs the user to open a password-protected archive, a method used to keep payloads encrypted until after initial inspection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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://onlinevay.com/upload/files/bibovofebewovukavuje.pdf In PDF document text
    • http://www.letnifestiwal.pl/ckfinder/userfiles/files/1596255434.pdfIn PDF document text
    • http://paramountswimwear.com/userfiles/files/2541696242.pdfIn PDF document text
    • http://udmvdpo.ru/images/files/jumolasonanozesagoxiraj.pdfIn PDF document text
    • http://kuhomania.ru/ckfinder/userfiles/files/sekivofada.pdfIn PDF document text
    • http://mentor-tutor.com/newGroserLikeProject/uploads/files/64590961014.pdfIn PDF document text
    • http://www.groupementpecheduloir.com/ckfinder/userfiles/files/92666834857.pdfIn PDF document text
    • http://ldkxzzs.com/images/userfiles/file/53113566193.pdfIn PDF document text
    • http://kperrylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/jiliwabumefone.pdfIn PDF document text
    • https://chrmglobal.com/userfiles/file/xetigepukatopeseza.pdfIn PDF document text
    • http://chingyi.tw/userfiles/files/devepiwutasoxoruw.pdfIn PDF document text
    • https://fabriziochessa.it/userfiles/file/xesuropixesovuvuxutoxug.pdfIn PDF document text
    • http://energo-market.ru/sadm_files/86023182931.pdfIn PDF document text
    • https://cmflower-kkc.com/ckfinder/userfiles/files/96446578829.pdfIn PDF document text
    • https://workinhotel.com/upload/fckfile/37958218806.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/16133a4880a0a5---fopupax.pdfIn PDF document text
    • https://www.milestonesmn.org/ckfinder/userfiles/files/19905361790.pdfIn PDF document text
    • http://speednewslive24.com/assets/ckfinder/core/connector/php/uploads/files/ramonikisemumosilekaliba.pdfIn PDF document text
    • http://dinobajka.pl/Upload/file/fawarivuragabifativirot.pdfIn PDF document text
    • https://hw-power.com/uploads/ckfiles/files/6138f90751f84.pdfIn PDF document text
    • http://shyjjc.com/v15/Upload/file/202191372808051.pdfIn PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613cd5531d889---kozesemonaz.pdfIn PDF document text
    • https://srsatta.com/ckfinder/userfiles/files/dasogijen.pdfIn PDF document text
    • https://mariellatriolo.it/public/file/lupani.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=open+rar+in+androidPDF 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_off0000ca99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA99 10096 bytes
SHA-256: 7250c20e633642edf4c39553b913033a8b831517369d0e78bae903c5ae5a2cce
font_01_sfnt_off0000e120.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE120 17648 bytes
SHA-256: a3e13d6c36df5ba3dd343c0b8ef930dcc857298b57da1b206240b16c7dbe1cc9
font_02_sfnt_off00010e59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E59 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1