Malicious PDF — malware analysis report

Static analysis result for SHA-256 52f931ce4720a72c…

MALICIOUS

PDF

75.2 KB Created: 2021-09-01 23:10:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: dbe9489e356690e4363a05f7fc838df1 SHA-1: e4339db3d28d97cebb7bfa39a2803cc03c9aa56f SHA-256: 52f931ce4720a72cdf9f89f0490f015249eacb0c39621823709a3c80bbd16083
156 Risk Score

Malware Insights

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

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier with high confidence. It contains numerous external URIs and link farm patterns, indicating an attempt to redirect users to potentially malicious websites. The presence of compromised CMS upload links further suggests a deliberate effort to host malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://synerhu.ru/uplcv?utm_term=hypocalcemia+in+infants+symptoms PDF link annotation
    • https://tomorrowhubs.com/upload/users/files/99946404547.pdfIn PDF document text
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/160740ef2e4f25---21749083257.pdfIn PDF document text
    • http://camelliafb.com/uploads//files/202108051042424704.pdfIn PDF document text
    • http://thaiboxes.com/piceditor/file/nutodegekezoz.pdfIn PDF document text
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b08f0e3fed9---jejunoxepirisuvirag.pdfIn PDF document text
    • http://mlkscholarshipsmilwaukee.org/clients/f/f0/f021f13c5c598389be7e913a1ae626ff/File/12604567448.pdfIn PDF document text
    • https://nevisnews.com/userfiles/dajaxaselowe.pdfIn PDF document text
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609521d927ccc---17092845144.pdfIn PDF document text
    • https://bataretak.com/img/files/file/xevewazegipidemalekedikep.pdfIn PDF document text
    • https://lightsourceindiana.com/wp-content/plugins/super-forms/uploads/php/files/5c75e71cac9dde65b8ad791b92e76e8f/7741862981.pdfIn PDF document text
    • http://waltwhitmanclassof1965.com/clients/c/cc/ccbfa8a87e297cd67510599b8aebcb74/File/95668320222.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/16094a4611b152---26461773007.pdfIn PDF document text
    • http://cpgny.com/userfiles/files/69571689988.pdfIn PDF document text
    • https://spencershaulageltd.co.uk/wp-content/plugins/super-forms/uploads/php/files/c95deb33621578d0c8dd6340801cd1f8/zopijurowaz.pdfIn PDF document text
    • http://erbilsunhotel.com/wp-content/plugins/super-forms/uploads/php/files/rhmqsm7mkkonc56s7n4lt1mlv2/89637900099.pdfIn PDF document text
    • http://harc-ias.vn/Images_upload/files/8767606439.pdfIn PDF document text
    • http://stinpo.com/ckfinder/userfiles/files/65162755789.pdfIn PDF document text
    • http://dmychadla.eu/UserFiles/File/12412578104.pdfIn PDF document text
    • https://benchmarktransitions.com/wp-content/plugins/formcraft/file-upload/server/content/files/16108f90623f1c---71105809158.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c57a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC57A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dd91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD91 10648 bytes
SHA-256: 81df1e411661a2e6a4dcfbfab2280664d2ea37c90e87f920f5d86cce184d75a2
font_02_sfnt_off0000f5eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5EB 16144 bytes
SHA-256: 02d164aa8c1b399ccd128875cf910739fc95759db11e5614152c60ace153730c