Malicious PDF — malware analysis report

Static analysis result for SHA-256 11228a3a385d6741…

MALICIOUS

PDF

83.4 KB Created: 2021-06-29 10:43:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ba74e2a706bc636b53a3b9bc813b3217 SHA-1: 05d23e9fb24e922234e5f68e3b4054de45689a26 SHA-256: 11228a3a385d67413d6db284dae1dbca23e93aa8b0759575ead305b27590d428
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of external URIs, many of which point to compromised WordPress upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and unreadable, providing no direct user-facing content, but the heuristic firings clearly point to a link farm designed to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://crewmak.ru/uplcv?utm_term=ssrs+dynamic+subreport
    • https://costabravas.com/uploads/localidades/files/lobedoliwidotinudowop.pdf
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078ad706cbd9---tagiwinujefurirapir.pdf
    • http://bensonlandscape.com/editorData/file/21602577745.pdf
    • https://nikosdimos.gr/userfiles/file/linexatatulipuviju.pdf
    • http://apexibd.com/uploads/fck_uploads/file/37250476126.pdf
    • http://bronia.org/userfiles/file/56524303272.pdf
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608fb6819a9df---bopino.pdf
    • https://pametnidom.hr/pametne_kuce/userfiles/file/zoxuxuk.pdf
    • https://precisionautoandac.com/wp-content/plugins/super-forms/uploads/php/files/3bae84a162f005a3f0729c4386e7fc1f/86581728292.pdf
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160711bfe1e032---18884392758.pdf
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160761099c9ad2---pefamikogofonitawome.pdf
    • http://bigband-ulm.de/userfiles/files/79204740128.pdf
    • http://mirrorgallery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608067607f10e---7625183241.pdf
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607eca54a1c48---59036669304.pdf
    • http://brenno-tojestto.pl/userfiles/file/44081858980.pdf
    • https://andrejc.si/files/file/lezibo.pdf
    • http://asbu.net/uploads/FCK_files/file/dupenujogabawupalaxino.pdf
    • https://www.parkgest.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1606f67ddcbe24---gozaxewume.pdf
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/jo55v1upemj7tohqmf4e4phsft/88213673313.pdf
    • http://cukierniabrzezinski.pl/www/artizam/fck/file/83452533510.pdf
    • https://amagi.la/wp-content/plugins/formcraft/file-upload/server/content/files/1608c9a8469364---leviwelixuxinurelis.pdf
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160bcdfc51d609---70798979669.pdf
    • https://dazzlin.co.uk/wp-content/plugins/super-forms/uploads/php/files/5bce65eb3f4cc7b4ca9c0c0440b6d84f/numewukipej.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_off0000e23c.bin
2dd4a683d622af4023764cdaf5bde5120b94abdce3c59bb956d7e4c392aa4213
pdf-font-stream PDF embedded font (sfnt) at offset 0xE23C 11060 bytes
font_01_sfnt_off0000fbc6.bin
b4055fd6851a7dbcc0c13ffffc4bed85342faa392a3236067db27ad45c678da5
pdf-font-stream PDF embedded font (sfnt) at offset 0xFBC6 17160 bytes
font_02_sfnt_off00012865.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12865 16792 bytes