Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9934a9e50ebca04…

MALICIOUS

PDF

85.2 KB Created: 2021-09-06 19:33:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: a96271f3a807a83eab32181fe637ec75 SHA-1: 3c44edc2efefd71ca66043116a11e82430d4e988 SHA-256: a9934a9e50ebca04ea22f39cb97bf674dd53f6afe27470daf2d5a31a35210b34
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains embedded JavaScript, which is often used to exploit PDF vulnerabilities or redirect users to malicious sites. Several URLs point to compromised WordPress upload directories, suggesting a pattern of using compromised infrastructure for hosting malicious content. The presence of embedded JavaScript and links to potentially compromised sites indicates an attempt to deliver a payload or phish users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • 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.
  • 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://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/1607f55939aa78---lulowaw.pdf In PDF document text
    • https://gonguyenkhoi.vn/upload/files/mipek.pdfIn PDF document text
    • http://nhatminhtrading.vn/app/webroot/uploads/files/16783339270.pdfIn PDF document text
    • https://bcbc3399.com/upload/files/talolug.pdfIn PDF document text
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606cd5e4b81af---35009387420.pdfIn PDF document text
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/b160f097489acc8471cbf5f54ff3b036/2815198267.pdfIn PDF document text
    • https://weeb.nu/userfiles/file/pogobigofotuzabinirukuw.pdfIn PDF document text
    • http://kaowei.tw/image/files/20210617_030152.pdfIn PDF document text
    • http://autowagon.it/userfiles/files/bubopafewipinelovixodew.pdfIn PDF document text
    • https://megatex.ua/images/uploads/file/bavofifipanosigefe.pdfIn PDF document text
    • http://solarissoft.com/img/userfiles/files/36265120309.pdfIn PDF document text
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607757571417f---79420011826.pdfIn PDF document text
    • https://rts-wm.com/ckfinder/userfiles/files/xuzoluw.pdfIn PDF document text
    • https://lawtutors.co.uk/js/ckfinder/userfiles/files/pujosibukodulibot.pdfIn PDF document text
    • https://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/2694d06bf40c3fcc3be131fda3ac94f6/84068133631.pdfIn PDF document text
    • https://k-kompany.ru/wp-content/plugins/super-forms/uploads/php/files/1600be7c1e1b5c1b438e3ef646aa5cfa/4831557186.pdfIn PDF document text
    • https://floridahouselottery.com/test/userfiles/file/54129191814.pdfIn PDF document text
    • http://udmvdpo.ru/images/files/zarironidibujakopetojexon.pdfIn PDF document text
    • http://cathugo.de/res/wysiwyg/file/21495956185.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086439ba95ec---968266413.pdfIn PDF document text
    • http://www.esthemed.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160a184dfdc48e---88950468519.pdfIn PDF document text
    • http://on-video.com/movies/movie_data/file/xakijiwiz.pdfIn PDF document text
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/13u62n2552aemam73qinj2c3ut/berukusaborugusise.pdfIn PDF document text
    • http://chnli.tw/CKEdit/upload/files/riwofiposevodulezojo.pdfIn PDF document text
    • http://xn--80affcyoc0ac1f6a.xn--p1ai/admin/modules/ckeditor/ckfinder/userfiles/files/55888157164.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=hong+kong+trail+map+pdfPDF 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_off0000e81e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE81E 10624 bytes
SHA-256: cb7e2941c3ed769327807137f0c116dd8cb51def2aa03c97151d1a8ca76d5e91
font_01_sfnt_off00010016.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10016 18120 bytes
SHA-256: d83ef0421f54e6caf05707624679ab1f797614d01668969b76baffed3bb23968
font_02_sfnt_off00012f03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F03 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1