Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc4393d1efea4070…

MALICIOUS

PDF

69.7 KB Created: 2021-09-20 18:25:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 5918f16a57cdbbd07ab89fb733ef9758 SHA-1: 0cbcaf69e42331a528ec094cd42f6248886a312f SHA-256: bc4393d1efea40700ca40f5b355213d742759c3ff9b43eb30f2e6460930b4555
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many pointing to potentially disposable domains, suggesting a link farm or phishing lure. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of an attempt to redirect the user to malicious content, likely for exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • 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.
  • 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://nuklearmedizin-amro.de/userfiles/file/2168070620.pdf In PDF document text
    • http://aaaexpressac.com/userfiles/file/pujunaj.pdfIn PDF document text
    • http://globalroomplus.com/bot/ckfinder/uf/files/dozugaleruvonuzabox.pdfIn PDF document text
    • http://urdu-hadith.com/survey/userfiles/files/xoririnexirewafovele.pdfIn PDF document text
    • http://stroytehcentr.ru/images/file/zakowekitovowulenevugo.pdfIn PDF document text
    • http://kiszelyugyvediiroda.hu/docs/file/73110353076.pdfIn PDF document text
    • https://1sis.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a3cf69f229---99064653771.pdfIn PDF document text
    • http://ptsound.com/plugins/ckfinder/userfiles/files/14046309225.pdfIn PDF document text
    • http://tecnoservizi.com/userfiles/files/96148339630.pdfIn PDF document text
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/1613567db93081---91846612494.pdfIn PDF document text
    • http://urduhadith.org/survey/userfiles/files/daneb.pdfIn PDF document text
    • https://femagnet.com/upload/edu/article/file/60193941935.pdfIn PDF document text
    • https://nomaquito-travel.com/editor-images/84221253627.pdfIn PDF document text
    • http://tienhasteel.com/app/webroot/upload/files/55101414241.pdfIn PDF document text
    • http://ahdongjiu.com/upload_fck/file/2021-9-14/20210914131429421320.pdfIn PDF document text
    • https://creativenursery.net/home/creative/public_html/ckfinder/userfiles/files/1676437216.pdfIn PDF document text
    • http://datong-travel.tw/upload/ckeditor/files/20210913085800.pdfIn PDF document text
    • https://jaukiaplinka.lt/ckfinder/userfiles/files/borosulanilijisirot.pdfIn PDF document text
    • http://alliance-ic.ru/uploads/file/xuniratusobimugofugevum.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/39qrs35evhte2i77jhd5sf3b14/83705392064.pdfIn PDF document text
    • https://rent-1.es/ckfinder/userfiles/files/13139281399.pdfIn PDF document text
    • http://stroyvodservice.ru/upload/File/roluxetu.pdfIn PDF document text
    • http://vansuloi.com/uploads/userfiles/file/memite.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=how+to+change+font+of+keyboard+in+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_off0000b1cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1CC 10964 bytes
SHA-256: 92e0ebecfaf8e032bd87230d9abe07bea12432cd447977319005c3da84d8efdd
font_01_sfnt_off0000cb02.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB02 15008 bytes
SHA-256: 0436470b168fb3195aec1a6d576776f8543e1060e2ad87fb70297ac94504d5f1
font_02_sfnt_off0000f10c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF10C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1