Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8e4676d1801f870…

MALICIOUS

PDF

78.5 KB Created: 2021-09-17 07:44:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: cdaa1c80b6eb57ba24c8b44c82bfde19 SHA-1: a3506c4bfa26a55aba964e02c888b09cdb246aa0 SHA-256: f8e4676d1801f870d6091d9f2b3d243cb09d89187382e97f54fdef9d59bb2dbd
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains embedded JavaScript and a large number of external URIs, many of which are hosted on disposable domains, indicating a link farm or phishing attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to redirect users to malicious sites or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://muahohangnhat.com/app/webroot/uploads/files/labarugo.pdf In PDF document text
    • https://samsungdvm.net/upload/ckfinder/files/13033563776.pdfIn PDF document text
    • http://lse.hu/userfiles/file/54148824417.pdfIn PDF document text
    • http://physocare.com/Images_upload/files/95604682923.pdfIn PDF document text
    • http://greatwalledmond.com/ckfinder/userfiles/files/zozikamevem.pdfIn PDF document text
    • http://thermogroup.ru/uploads/files/muzexakazamesidusetez.pdfIn PDF document text
    • http://pcserviszlin.cz/ckfinder/userfiles/files/miveseperijuropujaj.pdfIn PDF document text
    • http://dohertylaw.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/nazijumipi.pdfIn PDF document text
    • http://matchonusa.com/uploads/files/kotejokaliso.pdfIn PDF document text
    • http://gunjanjain.com/app/webroot/js/uploads/files/72158533052.pdfIn PDF document text
    • https://charming-dc.com/uploads/files/202109091916125759.pdfIn PDF document text
    • http://drprdesaihospital.com/uploads/37778083514.pdfIn PDF document text
    • http://chuabenhxuongkhop24h.com/images/files/38253322393.pdfIn PDF document text
    • https://walterchiropracticclinic.com/home/walter/public_html/ckfinder/userfiles/files/kosemesax.pdfIn PDF document text
    • https://guruamardaspublicschool.com/userfiles/files/furigafomorizo.pdfIn PDF document text
    • http://bsl-trans.ru/admin/ckfinder/userfiles/files/zijubepasokatazasumemuwiw.pdfIn PDF document text
    • https://sayurmateng.com/contents/files/82005700915.pdfIn PDF document text
    • https://mimpishio2bet.net/contents/files/tavuvowigapiliz.pdfIn PDF document text
    • http://zeamailer.zeapost.com/FCKeditor/editor/filemanager/connectors/userfiles/file/30938710308.pdfIn PDF document text
    • http://officinedesign.it/userfiles/files/3708883838.pdfIn PDF document text
    • https://incoyun.com/calisma2/files/uploads/setasowaboroliguvubepow.pdfIn PDF document text
    • https://sensesgrouphk.com/louis/STARKGROUP/ckfinder/userfiles/files/17940930310.pdfIn PDF document text
    • https://genia-groupe.fr/images/files/69492654924.pdfIn PDF document text
    • http://ubestsports.com/imager/files/20210910121832.pdfIn PDF document text
    • http://www.keizerco.nl/userFiles/file/xafoz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=dynamic+programming+lecture+notesPDF 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_off0000cbe1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBE1 17976 bytes
SHA-256: 5d710098b30e0f9691b3e6c37d9b581cc2ab8492922bfba40abff6044c1cdb63
font_01_sfnt_off0000faa9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAA9 10932 bytes
SHA-256: 7247ee65e3797d7086ca65eda83817c83ba29ab0d1ed68d8a2c8b363734d18e7
font_02_sfnt_off00011409.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11409 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1