Malicious PDF — malware analysis report

Static analysis result for SHA-256 8726ccf79680aaff…

MALICIOUS

PDF

109.3 KB Created: 2021-09-01 00:50:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: f31195d22fb4911bb378f41e8805f3df SHA-1: 5a2deb11c265bb8d64b90e28a71f93fe5e130b49 SHA-256: 8726ccf79680aaffe5af298c4e900d60a27b36fb9ece8dd3483dce6d14c52394
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous links pointing to compromised WordPress upload directories and other disposable hosting, suggesting a phishing or malware distribution campaign. The presence of embedded URLs and link farms indicates an attempt to redirect the user to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9084

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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://crewmak.ru/uplcv?utm_term=we+both+laughed+in+pleasure PDF link annotation
    • http://mgmkt.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c78fc3dc384---37475871728.pdfIn PDF document text
    • http://biomassasia.net/data_ed/userfiles/file/kasaduneguze.pdfIn PDF document text
    • http://perles-del-beya.com/userfiles/file/81577851072.pdfIn PDF document text
    • https://publicbridge.pl/userfiles/file/52377975754.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/valizosugupesapunoluw.pdfIn PDF document text
    • https://criteriacambio.com.br/wp-content/plugins/super-forms/uploads/php/files/ufp2nmn9kgue0ba9u1enqel8dl/5078732985.pdfIn PDF document text
    • http://elise.pe/images/file/zupuxu.pdfIn PDF document text
    • https://okazdedziecko.pl/_files/Media/file/kozesetajirukojesek.pdfIn PDF document text
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca419d6a1a---lenufasawifase.pdfIn PDF document text
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/880b498c94b9f0efb11b1724a2303b27/jarijalokoludaziw.pdfIn PDF document text
    • https://sidexsideaudio.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608540489f3a2---29788539109.pdfIn PDF document text
    • https://www.inter-tube.co.uk/wp-content/plugins/super-forms/uploads/php/files/35a3e952c6ab4ded84f9ee1aac500257/21867123233.pdfIn PDF document text
    • http://naturallabs.fr/userfiles/file/punugowope.pdfIn PDF document text
    • http://10glazsikeyrosa.ru/file/fovekot.pdfIn PDF document text
    • https://xlux.vn/wp-content/plugins/super-forms/uploads/php/files/h4rdbo48pfedt97bruo8sa9e5q/33366052824.pdfIn PDF document text
    • http://www.empresasdelimpeza.info/wp-content/plugins/formcraft/file-upload/server/content/files/160da7de29f7fa---51739120535.pdfIn PDF document text
    • http://www.redactordecontenidos.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160814831d4359---42583474760.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/16698844828.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/16085afc95022d---gibexozojelif.pdfIn PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1608532b51e025---sosinozajisi.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606ef4ff1d655---turuzuposogelisikute.pdfIn PDF document text
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/77ea329636c1de5452db617707a7c084/zefonuda.pdfIn PDF document text
    • http://mtsskzy.com/userfiles/file/21254638560.pdfIn 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_off00014ac1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14AC1 20452 bytes
SHA-256: 8397ce7d01058ec864f8f503213ec0182ead39b726cfa0de7213473409f4e72f
font_01_sfnt_off00017f5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17F5D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00019774.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19774 10904 bytes
SHA-256: e8f8018d13798fa0a8a75bfc72c4adf85a06ccc9689ed1b32c9f7c83ca7fe440