Malicious PDF — malware analysis report

Static analysis result for SHA-256 4da376ae9f55d4c1…

MALICIOUS

PDF

83.7 KB Created: 2021-09-12 09:48:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-27
MD5: 49560d9aca6182c56287d0178d394152 SHA-1: 3c4f5a9ed9de068b6188e950da911d36c80055c9 SHA-256: 4da376ae9f55d4c14331f79f80a9b52c76e4a0e25e90171a463089566e74f982
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, with high confidence. It contains embedded JavaScript, a common technique for executing malicious code within PDFs. The PDF also contains numerous external URIs, many pointing to potentially disposable domains, suggesting a link farm or phishing lure. The embedded JavaScript likely facilitates the redirection to these external URLs, which could host further malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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
  • 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://greenbins.ca/ckfinder/userfiles/files/pezepi.pdf In PDF document text
    • https://ku4ysk-9lgp4y.com/contents/files/fokanenuvo.pdfIn PDF document text
    • http://e3edu.vn/public/ckfinder/core/connector/php/connector.phppublic/uploadsfiles/fabupej.pdfIn PDF document text
    • http://p-jtech.com/userData/board/file/85584393437.pdfIn PDF document text
    • http://www.sctiec.com/up_files/FCK/file/roletuvuvisuredexipaxu.pdfIn PDF document text
    • https://insolite.lu/img/userfiles/files/gakawadisobixuzowekow.pdfIn PDF document text
    • https://oilbasaro.com/web/images/ckfinder/files/20210903062533.pdfIn PDF document text
    • http://hillsclinic.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/tuguwaduvusopitoxu.pdfIn PDF document text
    • http://jtravel.clickis.kr/FileData/ckfinder/files/20210911_E6D4A99C7B98617D.pdfIn PDF document text
    • http://winhazel.com/indigo/ckfinder/userfiles/files/batupex.pdfIn PDF document text
    • https://escaletravel.com/userfiles/files/bumepova.pdfIn PDF document text
    • http://npcbalkan.net/ckeditor/ckfinder/userfiles/files/xeritetadi.pdfIn PDF document text
    • https://bushregenerators.info/userfiles/files/61792882037.pdfIn PDF document text
    • http://sdds.be/userfiles/file/1392640920.pdfIn PDF document text
    • http://esejsc.com/upload/files/32779546227.pdfIn PDF document text
    • http://starcity-vinhomes.vn/app/webroot/img/files/zojabuxodameloxuparakoni.pdfIn PDF document text
    • http://aallergy.netlovestories.com/upload/files/vusegarepejomovuvu.pdfIn PDF document text
    • http://all-vehicle.net/js/upload/files/zaxatexijo.pdfIn PDF document text
    • http://lonerangerfanclub.com/ckfinder/userfiles/files/rexogopoxum.pdfIn PDF document text
    • http://bacsionline.net/userfiles/file/lanivazujepigitug.pdfIn PDF document text
    • http://er-trans.com/img/produkty/files/39554718557.pdfIn PDF document text
    • http://jiin-torng.com/uploadfiles/20210911235245.pdfIn PDF document text
    • http://brbud.pl/userfiles/file/67893347194.pdfIn PDF document text
    • http://pekingtogo.com/uploads/files/24519927896.pdfIn PDF document text
    • http://cortocircuito.trialpanel.com/images/Upload/files/83996871136.pdfIn PDF document text
    • http://asirakademi.com/resimler/files/52117753715.pdfIn PDF document text
    • https://kocarbon.vn/luutru/files/44636752101.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=hack+scr888+androidPDF 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_off0000e0c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0C1 10376 bytes
SHA-256: b8001a6f5ae931fb324ebc30bb29b49fa159204de38ecf8ba7278a07ca10d309
font_01_sfnt_off0000f84d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF84D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001105f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1105F 18672 bytes
SHA-256: 4d341ce166e3d5c9923291e796951b4f24a6d3712aa05fb7cad9b0cac913d8ea