Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf5e6b26c82cbaae…

MALICIOUS

PDF

67.4 KB Created: 2021-09-17 22:04:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 56013523639eba9526d048ace76e27d3 SHA-1: b0a2f972e65ff5a0fd7295b025c7535196ae42cb SHA-256: cf5e6b26c82cbaaeff009d0f810b1e7341ce990ce0e63afcddaec2bb2b2ac2a1
156 Risk Score

Malware Insights

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

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, with many embedded URLs pointing to external sites, some of which are hosted on compromised CMS uploads. The primary purpose appears to be directing users to potentially harmful content, consistent with phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • 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.
  • 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://vpsystem.com/files/fck/72751461408.pdf In PDF document text
    • http://ih-consultant.com/ckfinder/userfiles/files/5434292045.pdfIn PDF document text
    • http://tiga.co.th/ckfinder/userfiles/files/22969026262.pdfIn PDF document text
    • http://hiredriver.com/uploads/assets/files/vepegegug.pdfIn PDF document text
    • http://ohana1bbq.com/uploads/files/jinazubukebaxajun.pdfIn PDF document text
    • http://sten.kr/club/data/userfiles/file/20210916134323.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/wutejoradubamuzomivawidu.pdfIn PDF document text
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613320b3b10c6---66414412040.pdfIn PDF document text
    • http://yourtruck.be/upload/ckeditor/file/nufefuta.pdfIn PDF document text
    • http://kerama.altrodesign.eu/ckfinder/userfiles/files/toreliped.pdfIn PDF document text
    • https://fenicia.uy/fenicia.com.uy/uploads/files/minotojez.pdfIn PDF document text
    • https://trompis-tondschungel.de/userfiles/file/xinofej.pdfIn PDF document text
    • http://ydis.kr/userfiles/file/131950368259.pdfIn PDF document text
    • https://greenboo.vn/uploads/files/vumunumoz.pdfIn PDF document text
    • https://www.partyshuttlebus.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161413de7602d7---rerefasagikum.pdfIn PDF document text
    • http://vipdiler.ru/files/file/fokuroko.pdfIn PDF document text
    • https://indianhairtransplant.com/ckfinder/userfiles/files/relujivemix.pdfIn PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161398d22e9d71---22406743099.pdfIn PDF document text
    • https://csp-pub.com/stockages/files/tipemamanoredil.pdfIn PDF document text
    • http://retailcop.ca/files/moxakazuxanewulek.pdfIn PDF document text
    • http://kedehg.com/ckfinder/userfiles/files/72976377198.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=movie+download+websites+for+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_off0000abf8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xABF8 14288 bytes
SHA-256: 64b26aa322ef86b253b45350946445c9277ebf301f1e0a74bd6dd1d1fdbacaba
font_01_sfnt_off0000cfaa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFAA 10632 bytes
SHA-256: e23389579d0e046817ce97674e62ff293c337293d67eb6bf976ee519cf9f3b81
font_02_sfnt_off0000e831.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE831 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1