Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8643ec1715ad88b…

MALICIOUS

PDF

76.2 KB Created: 2021-09-03 02:01:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: e6c295afde341c07b76838e57e882bf6 SHA-1: c3c1cf55fd8d9899fcb49dfa0fc522a02cf90b2a SHA-256: a8643ec1715ad88be7f631aef14c446641941b906f7080c506dc21e9850eb040
124 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected by ClamAV as Pdf.Phishing.Trojan. It contains numerous embedded URLs, many of which point to compromised WordPress upload directories or are hosted on disposable domains, characteristic of a link farm used for phishing or malware distribution. The PDF document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier suspicious score 0.4752

Heuristics 5

  • 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
  • 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://www.cerathai.com/image/upload/File/defera.pdf In PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a83af485451---bojejinop.pdfIn PDF document text
    • http://verkaufs-akademie.com/userfiles/file/62971894126.pdfIn PDF document text
    • https://akanaymatbaa.com/calisma2/files/uploads/81945218653.pdfIn PDF document text
    • https://moto-trend.cz/public/files/fck/file/sujukipimus.pdfIn PDF document text
    • http://pretaporter-pegah.com/userfiles/file/boxexapilij.pdfIn PDF document text
    • http://ty-universe.com/image/files/20210716_095614.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d031f793b3---wudot.pdfIn PDF document text
    • https://ksmt.edu.np/assets/ckfinder/userfiles/files/18660262633.pdfIn PDF document text
    • https://imapcb.org/wp-content/plugins/super-forms/uploads/php/files/2oliv4atkl7ggqj383hfsqroe1/46649109942.pdfIn PDF document text
    • http://shopexpert.com/app/webroot/files/userfiles/files/94454045989.pdfIn PDF document text
    • http://www.advokat.com/app/webroot/img/fck/file/5862760827.pdfIn PDF document text
    • https://iqmuseum.mn/uploads/files/puragojeweger.pdfIn PDF document text
    • http://longhornrings.com/clients/0/08/08da48574b41509ac7bedcf2500dc652/File/19409048552.pdfIn PDF document text
    • http://falconfam.com/ckfinder/userfiles/files/bixekebumexotigunetapigo.pdfIn PDF document text
    • http://www.roosprommenschenckelfoundation.nl/ckfinder/files/files/risemubopozizefemekejonoj.pdfIn PDF document text
    • http://trickorsuite.com/clients/5/5d/5d84d12f6f4dfd10bbe5497c884a5f3e/File/tokomo.pdfIn PDF document text
    • http://15881588.com/ckupload/files/85693594658.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160c24dd16c0e7---kojujudabobolebopuxojewof.pdfIn PDF document text
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/abf77ad9c6921d32460ba1e3ca6c1c28/64791069713.pdfIn PDF document text
    • https://comesa.com.pe/wp-content/plugins/super-forms/uploads/php/files/dgjcgeglgm3tdf8umceqdk4o33/pinuluzekazaxa.pdfIn PDF document text
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090a1122086b---rojevazosisigusemoto.pdfIn PDF document text
    • http://clinicaveterinariasangiacomo.it/userfiles/files/jumevubigajelomazenir.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=pancreatite+aguda+pdf+uspPDF link annotation
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dff6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFF6 10732 bytes
SHA-256: 9ebe873542142fec8d7ebd2a25b3e729b2d782f0cf53cf53091da806b8d034f2
font_01_sfnt_off0000f893.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF893 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1