Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4ef94a88e4acef8…

MALICIOUS

PDF

71.0 KB Created: 2021-09-30 16:02:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 1578c61b46a43238571b38a6c212cad9 SHA-1: d46d1004382b26f5a68c6659e5650f1f843d8144 SHA-256: c4ef94a88e4acef817a9617ef47ad7024e8543a1648cdc5151266b9ebc8f3cce
154 Risk Score

Malware Insights

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

The sample is a PDF containing embedded JavaScript, flagged by ML classifiers and ClamAV as malicious. It exhibits characteristics of a link farm, with numerous URLs pointing to disposable domains, suggesting an attempt to distribute malicious content or phish users. The presence of embedded JavaScript indicates potential for further malicious actions, such as downloading additional payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 7

  • 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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 http://aurora-c.jp/files/files/3360142885.pdf In PDF document text
    • https://digireg.pl/upload/57727806504.pdfIn PDF document text
    • https://mimpiindah2.com/contents/files/46001834023.pdfIn PDF document text
    • http://xn--9i1b14l32gg2dsybq3b.com/upload/fckeditor/file/kekot.pdfIn PDF document text
    • http://www.realisthotel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161421cc427771---bowilubumixotezagodaveras.pdfIn PDF document text
    • http://www.nagsa.es/ckfinder/userfiles/files/poxufelulako.pdfIn PDF document text
    • http://carshopm.com/js/upload/files/22888429638.pdfIn PDF document text
    • https://takitech.hu/userfiles/file/90966553710.pdfIn PDF document text
    • http://xn--90aoaidn.xn--p1ai/ckfinder/userfiles/files/vebebutasitu.pdfIn PDF document text
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16150ab08b03d4---viweraba.pdfIn PDF document text
    • http://mapect.com/upload/fckeditor/file/1060601632.pdfIn PDF document text
    • https://www.ccs-corporation.com/ckfinder/userfiles/files/lilopof.pdfIn PDF document text
    • https://ebmcordelles.progess.com/userfiles/file/dumajuveniterinedutoj.pdfIn PDF document text
    • http://sictombbi.fr/ckfinder/userfiles/files/sojiraz.pdfIn PDF document text
    • https://relaxbotanika.cz/ckfinder/userfiles/files/796448440.pdfIn PDF document text
    • http://www.zywawiara.pl/pliki/vovavotazanukukozo.pdfIn PDF document text
    • https://discovercefalu.it/_data/images/file/9825824805.pdfIn PDF document text
    • http://rutka.pl/media/upload/files/33106a59e8868324c0d1c0b09bcf7869.pdfIn PDF document text
    • http://budapesticukraszdak.hu/userfiles/files/pokugidazidozaso.pdfIn PDF document text
    • http://yidaig.com/uploadfile/file/20210916003637.pdfIn PDF document text
    • http://engcaphone.com/_UploadFile/Images/file/22725616818.pdfIn PDF document text
    • http://portakalweb.net/home/portakal/public_html/ckfinder/userfiles/files/86209382404.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=qr+code+barcode+scanner+apkPDF 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_off0000b1ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1AB 10564 bytes
SHA-256: 9e332fc4f1a2281836313de29855f903b7d159cf5068fe818a054b042371129b
font_01_sfnt_off0000c9b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9B2 17224 bytes
SHA-256: 36341c5ea1899caaa3468ff708944566e7aa635cefafee4572f5f830283ff4eb
font_02_sfnt_off0000f5f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5F8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1