Malicious PDF — malware analysis report

Static analysis result for SHA-256 5cfcf41b4db971f0…

MALICIOUS

PDF

99.9 KB Created: 2021-09-18 10:03:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: f17bd0eb4828c53475b2c06af45cae45 SHA-1: c7f9090f52e9a85c41e3da9494d0ac475833d3c1 SHA-256: 5cfcf41b4db971f08db4abe4e2c65ee71074099b552b0923a6b7cb8a81cc8af1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, exhibiting characteristics of a link farm. It contains numerous URLs pointing to various domains, some of which are associated with compromised CMS uploads or disposable hosting, suggesting an attempt to lure users to potentially malicious sites. The PDF structure and embedded URLs are indicative of a phishing or malware distribution attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9936

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 https://irlanc.ru/uplcv?utm_term=friends+reunion+live+streaming PDF link annotation
    • http://ckudzcssffhhj.handysociality.com/upload/files/14271443045.pdfIn PDF document text
    • http://bubb.cn/up_file/file/savoliromuvubisov.pdfIn PDF document text
    • https://sanidom.pl/img/file/titepipexarinovugojotibu.pdfIn PDF document text
    • https://nceptionsolutions.com/wp-content/plugins/super-forms/uploads/php/files/4dee71abbdbe40bd14e7278a399a7df0/fonozejemasikere.pdfIn PDF document text
    • https://philly.drinkpoint.com/uploads/files/51705604268.pdfIn PDF document text
    • http://tribo.kz/userfiles/File/mukusoku.pdfIn PDF document text
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613912a389c64---jovej.pdfIn PDF document text
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/161437d7f881b5---jagatanasup.pdfIn PDF document text
    • http://ihdbd.org/upload/files/35066506166.pdfIn PDF document text
    • https://www.tristar-technology.com/ckfinder/userfiles/files/21652055310.pdfIn PDF document text
    • http://www.amedna.com/userfiles/files/wavasupasibi.pdfIn PDF document text
    • http://dream-mebel.com/pic/file/64079701545.pdfIn PDF document text
    • http://upnbkk.com/file_media/file_image/file/11240349108.pdfIn PDF document text
    • http://projecthouse.bg/uploads/CKfinder/files/53185328618.pdfIn PDF document text
    • http://xn--b1adcbbai1bezln.xn--p1ai/content/File/fidutobiraje.pdfIn PDF document text
    • http://newbusan.net/FileData/ckfinder/files/20210909_667EEDAE4350418A.pdfIn PDF document text
    • https://agrando.cz/files/file/badedolipefu.pdfIn PDF document text
    • http://www.koeru.eu/failid/file/74248926503.pdfIn PDF document text
    • http://iknow.pl/files/file/64680061415.pdfIn PDF document text
    • http://goldstecq.com/userfiles/file/10343229275.pdfIn PDF document text
    • http://protech.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/1612ef7ee1e160---wagipasapepuzewe.pdfIn PDF document text
    • https://medtek.vn/storage/file/94802086978.pdfIn PDF document text
    • https://hotellemaritime.com/hotel/upload/files/siwesisawuroniwi.pdfIn PDF document text
    • 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_off00012113.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12113 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001392a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1392A 10732 bytes
SHA-256: 7c0359fe9bf1d56a841f78b53d79265d83c3865495717b98a957726e327e87b7
font_02_sfnt_off00015196.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15196 18568 bytes
SHA-256: c6678c1ed88674288e57414f5bddbdc0e0d00f3a942c7fe93b6a052c4e1a1061