Malicious PDF — malware analysis report

Static analysis result for SHA-256 f76bd621bd297f40…

MALICIOUS

PDF

78.6 KB Created: 2021-09-11 17:19:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 6ce4d99615f4425c9e2d82bb6065b992 SHA-1: 06a4cfc01f0e2b53898d25424bdbfb58dc1eade4 SHA-256: f76bd621bd297f40070d257e347845a3e18631213cbbe744b9cc70df587384da
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The presence of numerous external URIs, many pointing to PDF files on various domains, suggests a link farm designed to redirect users. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest it's a phishing or malware distribution lure, likely leveraging embedded JavaScript to facilitate redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • 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.
  • 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://orderpoet.com/ckfinder/userfiles/files/43723535048.pdf In PDF document text
    • http://goddesshair.net/upload/users/files/57006598723.pdfIn PDF document text
    • http://ventilatoryzlin.cz/images/file/77002508931.pdfIn PDF document text
    • http://favorit.pl/userfiles/file/tekavuvezububowitikemabek.pdfIn PDF document text
    • http://www.niceresidence.net/image/upload/File/kirobulubawikeli.pdfIn PDF document text
    • http://hongsung114.com/files/fckeditor/file/49712363755.pdfIn PDF document text
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161366a6b3a9d5---51297855339.pdfIn PDF document text
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139fd641318f---xomuwozoxudotubawinez.pdfIn PDF document text
    • http://roberlo.cz/www/files/file/37152250945.pdfIn PDF document text
    • http://usmleworkout.com/files/file/tasofakekemanexuzuditiza.pdfIn PDF document text
    • https://samudra99.com/contents/files/kigitigoxavegefe.pdfIn PDF document text
    • http://omatsuri.kr/data/userfiles/files/53069781078.pdfIn PDF document text
    • http://termocity.by/pics/files/xawewara.pdfIn PDF document text
    • https://xn----7sbeo1acdy3adh.xn--p1ai/userfiles/file/firezisopuw.pdfIn PDF document text
    • https://12shio1.com/contents/files/39199004528.pdfIn PDF document text
    • http://obras.ru/sites/default/files/uploads/75966251521.pdfIn PDF document text
    • http://escrima-rlp.de/userfiles/file/dekesibow.pdfIn PDF document text
    • https://facades-et-traditions.com/actualites/file/jipobej.pdfIn PDF document text
    • http://interstyle.org/content/xuploadimages/file/50931435049.pdfIn PDF document text
    • http://quesnelfoundation.ca/userfiles/file/tuzujalavodozunogowitewer.pdfIn PDF document text
    • https://rumputhijau.com/contents/files/86811989115.pdfIn PDF document text
    • https://kamionosnyelvlecke.hu/userfiles/file/2783383810.pdfIn PDF document text
    • http://marinaxaraes.com.br/ckfinder/userfiles/files/sakujikirevu.pdfIn PDF document text
    • https://fokusmedia.com/images/uploads/kurenikaw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=where+is+my+phone%27s+recycle+binPDF 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_off0000cfbc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFBC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e7d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7D3 10660 bytes
SHA-256: 89e3dd8ba115f3871083d2e327971971c3eac9ea4730b0670d610dde87c0d3a3
font_02_sfnt_off0000ffdf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFDF 17236 bytes
SHA-256: a09d7e2c00ca93d6ae8789d1e1395c2c4721a93a37e68cf905c81c930f7968a2