Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef13c4d832079448…

MALICIOUS

PDF

60.2 KB Created: 2021-09-01 23:21:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: f33d666b739b2cf460a15f1513830b62 SHA-1: 0918470e591215418e3a9ea41e7562865efc74be SHA-256: ef13c4d832079448e45c3d68c4ade24e3217b14e65f29e6a99bf97f94d7ee311
94 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites acting as link farms. The ML classifier also flagged this PDF as malicious. While no scripts were directly extracted, the presence of a link farm on compromised infrastructure suggests an attempt to redirect users to malicious or phishing content, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8980

Heuristics 4

  • 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://thietkewebbacninh.com/webroot/img/files/62075461040.pdf In PDF document text
    • http://fmmvn.net/userfiles/files/geziv.pdfIn PDF document text
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b64877a8f5b---92806246111.pdfIn PDF document text
    • https://thealloywheelcentre.co.uk/wp-content/plugins/super-forms/uploads/php/files/dd3b26ee1674a4408f3d5a3a15a5d394/razigibukubo.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f230662dcd---xisafuxotobizasa.pdfIn PDF document text
    • http://bienbao.org/uploads/files/20934617936.pdfIn PDF document text
    • https://www.perfumista.co.uk/wp-content/plugins/super-forms/uploads/php/files/01bb76c9afe2e537db1bf7ad47533f67/nibeguxokaditinixabufuju.pdfIn PDF document text
    • http://alarcon-v.com/editor_upload_image/file/suzogufevoked.pdfIn PDF document text
    • https://robinio.de/wp-content/plugins/super-forms/uploads/php/files/vrbuhisf7bh3i09f1pphqoaskj/58428772713.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161237409c4d16---pokekatujit.pdfIn PDF document text
    • https://rhdplumbing.com/wp-content/plugins/super-forms/uploads/php/files/741bbee54a324beb7b80730ea9674ef8/pifamafuvawadesadixipotuw.pdfIn PDF document text
    • https://dananeye.com/uploads/files/202108211845502284.pdfIn PDF document text
    • http://personal.sut.ac.th/chantira/port/ckfinder/userfiles//files/segexibapasuwumofif.pdfIn PDF document text
    • https://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/df6c329e20295374fb61f63efdfff616/24836088208.pdfIn PDF document text
    • http://garderoba.sk/images/_file/20685813152.pdfIn PDF document text
    • http://ylplj.com/ckfinder/userfiles/files/20498064942.pdfIn PDF document text
    • https://arvikabc.com/images/uploadedimages/file/tedubegulosejonezemij.pdfIn PDF document text
    • https://careersourcechipola.com/files/public/52261467730.pdfIn PDF document text
    • https://rosemonttherapy.health/wp-content/plugins/super-forms/uploads/php/files/5a107kgae6455l1ejj6gtbbpr6/1490487523.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1608d29532de8d---guwokavererusonuti.pdfIn PDF document text
    • http://sgpeo.pl/users/file/38481119359.pdfIn PDF document text
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160776b90cf114---mawepokisijajamotoj.pdfIn PDF document text
    • http://lotuscourtpune.com/wp-content/plugins/super-forms/uploads/php/files/p135ofb10k4ck7fr2f3sran6b6/61719259876.pdfIn PDF document text
    • https://hafa-verein.de/wp-content/plugins/super-forms/uploads/php/files/c2bcc80431ebd105234be45f831385f3/xadunugikajeko.pdfIn PDF document text
    • http://vipnjl.com/userfiles/files/1866447469.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=happy+trails+by+roy+rogers+and+dale+evansPDF link annotation
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d4c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4C1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1