Malicious PDF — malware analysis report

Static analysis result for SHA-256 ab31a7e73a5ce169…

MALICIOUS

PDF

74.0 KB Created: 2021-09-18 07:53:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f5ca65efaed65777204bcc547f6de8e6 SHA-1: 0baab6bf2f78441ec49fb8317f5157225222eec4 SHA-256: ab31a7e73a5ce169f422e168c2cbcc3f8af3918bfb7c81713636576dc417127a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, with several heuristics indicating a link farm hosted on compromised CMS uploads and disposable hosting. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious document lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://intimatehotelpattaya.com/image/upload/File/xakexel.pdf
    • http://icsbc.ru/fuploader/file/76108310786.pdf
    • https://fond.ru/userfiles/file/jukew.pdf
    • http://eltprof.ru/userfiles/file/19201141446.pdf
    • http://delfosventures.net/userfiles/files/nuwisunivebidelufuwokaji.pdf
    • https://rux-thai.com/ckfinder/userfiles/files/15997459108.pdf
    • https://www.akilciilacdernegi.com/ckfinder/userfiles/files/44692281047.pdf
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/161376df19b7f6---34024051664.pdf
    • https://whatproperty.ng/ckfinder/userfiles/files/85371563039.pdf
    • http://eaas-journal.org/survey/userfiles/files/68365531689.pdf
    • http://karpatskiles.ru/store/files/73913394930.pdf
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613ad6435a33d---37785939367.pdf
    • http://oresteruggiero.com/userfiles/files/56234978709.pdf
    • http://www.first-classlogistics.com/image/upload/File/surezoretirivub.pdf
    • http://anbao.vn/uploads/userfiles/file/27652620128.pdf
    • http://df-2.de/images/daten/file/wazojapewasawut.pdf
    • https://luatsubienhoa.com/upload/ck/files/memefoxugotomujuraw.pdf
    • http://jd6618.com/jd6618/file/2021-9/file/LwpCms2021_09_12_04_13_07_1360.pdf
    • https://socardan.com/userfiles/files/zepif.pdf
    • https://vsevolozhsk.mebel18.com/uploads/files/61567536559.pdf
    • https://sharmtocairo.com/userfiles/files/denabatikixamorapapab.pdf
    • http://matrixuniverzum.eu/wp-content/plugins/formcraft/file-upload/server/content/files/161346020d0c80---jipuxadeke.pdf
    • http://ever0036.com/assets/uploads/ckedit/files/20210907192436.pdf
    • http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613e77bf82811---95802079139.pdf
    • https://alquimia.in/admin/fckeditor/editorfile/76336105816.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=android+download+manager+tutorial
    • 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_off0000be4c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xBE4C 16792 bytes
font_01_sfnt_off0000d65e.bin
efe2c899b4508aa03e048a31b70df6ce363703ec28b2a3a32e36dcc83e5f1a6d
pdf-font-stream PDF embedded font (sfnt) at offset 0xD65E 16968 bytes
font_02_sfnt_off00010228.bin
9338980d7e395537de72c761e9737577cd93f4d2207c061a2bda6b9289f450ad
pdf-font-stream PDF embedded font (sfnt) at offset 0x10228 10592 bytes