Malicious PDF — malware analysis report

Static analysis result for SHA-256 4cdf4cc19e762ca6…

MALICIOUS

PDF

69.4 KB Created: 2021-09-28 11:05:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 1511ddb15160ccc0345a7ca5671200d2 SHA-1: 7a80e936f99bf8d2730496f62a0eea5ad47ada1c SHA-256: 4cdf4cc19e762ca66010ee6e28c5e82086fcd37e8d762f0fda08bb59b3787701
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, with several heuristics indicating it functions as a link farm. Some of these links point to compromised CMS upload directories, suggesting an attempt to lure users to malicious content or phishing sites. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

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://listocrm.com/userfiles/files/7153169525.pdf In PDF document text
    • http://aal.tw/uploads/htmlupload/files/77716151081.pdfIn PDF document text
    • http://nhac.ditimchanly.org/Images_upload/files/dobitozalewiwopulonofosi.pdfIn PDF document text
    • http://mayinmaunhat.com/upload/files/jipavexijariwowuwalekatuk.pdfIn PDF document text
    • http://0985028898.kad.tw/kads/ckfinder/userfiles/files/retugidinexugele.pdfIn PDF document text
    • https://hahapediatric.com/uploads/files/202109030248279553.pdfIn PDF document text
    • https://tvmreza.tv/ckfinder/userfiles/files/pixuvamoxamodumanipa.pdfIn PDF document text
    • http://virtualcharityevents.com/vce_cake/files/files/jagetalanik.pdfIn PDF document text
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/rujebumasakuram.pdfIn PDF document text
    • http://preciz.com/uploads/wysiwyg/files/37022902558.pdfIn PDF document text
    • http://harchovyk.com/userfiles/file/43996797298.pdfIn PDF document text
    • http://ourgans.org/userfiles/files/xowekibo.pdfIn PDF document text
    • http://generaltubi.com/container/ckfiles/files/1956957351.pdfIn PDF document text
    • http://thermcom.cz/userfiles/file/lupejejijepafoxu.pdfIn PDF document text
    • http://bananamusic.tw/uploads/files/202109221343087069.pdfIn PDF document text
    • http://topimmigrationlawyer.org/ckfinder/userfiles/files/31157842064.pdfIn PDF document text
    • http://zit-tech.com/userfiles/files/39313865460.pdfIn PDF document text
    • http://www.homefacelifters.com/wp-content/plugins/super-forms/uploads/php/files/6212d9ff3373e678db662897e0085521/fixujagek.pdfIn PDF document text
    • http://ozanatalan.com/iboard/includes/userfiles/files/93528337222.pdfIn PDF document text
    • http://ccspatti.org/userfiles/file/22984389151.pdfIn PDF document text
    • http://okna-kurska.ru/page_edit/_samples/userfiles/files/volirarumetep.pdfIn PDF document text
    • https://www.alertgy.com/wp-content/plugins/super-forms/uploads/php/files/7b3dc4a551b01ceeedfd6e1bdf8fbab9/94406623902.pdfIn PDF document text
    • https://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/6pqbvpasvca18ejqqc2fsdcmar/safejixobun.pdfIn PDF document text
    • http://yummyschool.com/_UploadFile/Images/file/vexobuxopalunebagu.pdfIn PDF document text
    • https://esz.jp/img/editor/files/2896320938.pdfIn PDF document text
    • http://nollve.com/img/editor/image/file/79406435333.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=robux+promo+codes+redeemPDF link annotation
    • 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_off0000b139.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB139 15304 bytes
SHA-256: fdfe7da3b98342ed5c9520634173ce2aa44e3501495105fafd57ce772d5b24a2
font_01_sfnt_off0000d7e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7E6 10560 bytes
SHA-256: 93730372a7ee1a26b809953fc1a73519b8640cbcfa903235c29961b313452ed4
font_02_sfnt_off0000efd2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFD2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1