Malicious PDF — malware analysis report

Static analysis result for SHA-256 7c40d5b770322a76…

MALICIOUS

PDF

77.1 KB Created: 2021-09-16 05:09:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: fdd2b835147b847509fd596efefccc76 SHA-1: fe83911dfcf4ff973e834f11ab23869f57884396 SHA-256: 7c40d5b770322a763470bfaad6f87dffc17c4e682b1c6bc2b846adfb73ade463
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing or trojan. It contains a link farm with numerous URLs pointing to PDF files, many hosted on disposable or potentially compromised domains. One heuristic specifically identifies a link farm pointing to compromised WordPress upload storage, suggesting a tactic to disguise malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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
  • 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 http://xn--e1aazeoc7d.xn--p1ai/images/shared/file/zevudonal.pdf In PDF document text
    • http://tuecpa.com/file_media/file_image/file/4927744108.pdfIn PDF document text
    • http://nickelsgrafikdesign.de/ckfinder/userfiles/files/gapusifasumazokudoworik.pdfIn PDF document text
    • http://innovatepc.com/userfiles/file/66854382983.pdfIn PDF document text
    • http://actinq.nl/upload/file/73403300645.pdfIn PDF document text
    • http://stuarteisbrucklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/99307010476.pdfIn PDF document text
    • http://toyotarent.hk/FileData/ckfinder/files/20210908_FF42C2C4B6F7FC51.pdfIn PDF document text
    • https://fa-vietnam.com/webroot/img/files/84475544905.pdfIn PDF document text
    • http://hylimusic.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/lusidus.pdfIn PDF document text
    • http://miydz.com/mingyi/images/userfiles/file/kobobotun.pdfIn PDF document text
    • http://www.lukoilmarine.com/ckfinder/userfiles/files/bamoger.pdfIn PDF document text
    • https://kaptenhoki.info/contents/files/25165336644.pdfIn PDF document text
    • https://cordovajewelry.com/images/file/87979463071.pdfIn PDF document text
    • http://flomojapan.com/upload/files/27727602764.pdfIn PDF document text
    • http://matrixuniverzum.eu/wp-content/plugins/formcraft/file-upload/server/content/files/161352a9832326---kamamuvemuvowogejenakapur.pdfIn PDF document text
    • http://md-servicios.com/userfiles/file/ginurew.pdfIn PDF document text
    • https://aguiapromocional.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16130420b121d9---85750519975.pdfIn PDF document text
    • https://baongochoa.com/upload/file/tabelewumuwitud.pdfIn PDF document text
    • https://ketdoanbus.com/webroot/img/files/volosikilumupi.pdfIn PDF document text
    • https://maintogelonline.bet/contents/files/jolunubaguj.pdfIn PDF document text
    • http://zulassung4you.de/bilder/file/dunimam.pdfIn PDF document text
    • http://ambulatorioveterinariorigolon.eu/userfiles/files/27062438945.pdfIn PDF document text
    • https://trichynext.com/wp-content/plugins/super-forms/uploads/php/files/b002661c556d5512208db6f9d12199b3/dizedolalegevuroduma.pdfIn PDF document text
    • https://sukienmiennam.com/userupload/files/83708626540.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=backup+sms+messages+from+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_off0000ca3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA3D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e254.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE254 11064 bytes
SHA-256: 8f21d942b00b771f6a891bf953732e8585fef3ba8ac47ba2906b14feed19c394
font_02_sfnt_off0000fbe3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBE3 16556 bytes
SHA-256: e902b1c1233bd99c546a1264af8e7c42faed09b8da00bcb60b738fcbc1e2cda8