Malicious PDF — malware analysis report

Static analysis result for SHA-256 84324fe0c77b9fff…

MALICIOUS

PDF

82.4 KB Created: 2021-06-28 08:26:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: bf20373527632c3185508e9a11ec6494 SHA-1: 2456634e9623e2bd1f23efcf709ec7feb62384e1 SHA-256: 84324fe0c77b9fffefbfe1b8e949758900c0279535e266c2ec36618131234c1a
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The numerous embedded URLs point to compromised CMS uploads and disposable hosting, indicating a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf, further suggesting a malicious intent rather than legitimate document content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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
  • 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 https://smidgel.ru/uplcv?utm_term=dysentery+water+borne+diseases
    • https://mlbcsimleague.com/ckfinder/userfiles/files/9278837337.pdf
    • http://etasystem.net/userfiles/files/punototav.pdf
    • http://akvatoria.by/UserFiles/files/6831034159.pdf
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609bff2f994e9---19955371963.pdf
    • http://derkwoo.com/upload/editor/files/manazifalejo.pdf
    • http://educationexplosion.com/clients/a/aa/aae59ec6301d25964842a0067e0ae100/File/dujadoxirakor.pdf
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607ab9cbb475a---22878892192.pdf
    • https://cls-toronto.com/wp-content/plugins/super-forms/uploads/php/files/770cf367cd65920e28891871a5076d22/57435485638.pdf
    • http://hgbs.de/userfiles/file/65197273610.pdf
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607970a9ae81f---ritinilelu.pdf
    • https://vieclambanhang247.com/upload/files/98877044407.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4d304491fe---52169346029.pdf
    • http://huh.hu/UserFiles/File/fefubimegegawumevebuzug.pdf
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d2cbc6a5d9---42679504831.pdf
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/c2562ea23e9ca809edf6c1b5b40fa843/96776873549.pdf
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d8d09b9ba5d---35944423999.pdf
    • http://pspectr.ru/userfiles/file/34812413910.pdf
    • http://www.restorationservice.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a86bf142d40---36621428503.pdf
    • http://zaun-produzent.de/userfiles/file/30494045411.pdf
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/t95j0srlplmh6uh4c8g3co86j3/kavumozidu.pdf
    • https://nicemexico.net/wp-content/plugins/formcraft/file-upload/server/content/files/160714116d0b53---jixafivabizadom.pdf
    • http://www.justgiveahand.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a4d5404b627---68307726088.pdf
    • http://www.socalgreatwhite.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e5991d7aa4---35238437647.pdf
    • http://basaritarim.net/admin/editor_resim/file/61477062839.pdf
    • http://anonelectronics.com/admin/fckeditor/editor/filemanager/connectors/php/upload_jpg/file/202105161747415160.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000deb3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDEB3 16792 bytes
font_01_sfnt_off0000f6c5.bin
01e8217a605d65bbd63cb513dbf1e43542ead6a89c1ee6c6d790b22975c8b139
pdf-font-stream PDF embedded font (sfnt) at offset 0xF6C5 17304 bytes
font_02_sfnt_off000123ec.bin
133c45b3fcd13e182d4c3b8f835e75c9bdc0d73161120ab1d11e62cf4b5e97b0
pdf-font-stream PDF embedded font (sfnt) at offset 0x123EC 10536 bytes