Malicious PDF — malware analysis report

Static analysis result for SHA-256 ab9500996f5d1291…

MALICIOUS

PDF

72.0 KB Created: 2021-09-18 22:03:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 7600e3af914085affa0a304759c034dc SHA-1: 5503d49f2ca1c782d238fc2e5c6c12567c154062 SHA-256: ab9500996f5d1291c1d1796b05a47610254d66553166f7092121518150fd5161
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier. It contains a link farm with numerous URLs pointing to PDF files hosted on compromised WordPress sites and other disposable domains. The document body is heavily obfuscated, but the presence of these links suggests a phishing or malware distribution attempt, likely leveraging the compromised sites to host malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://chunmianxian.com/upfolder/e/files/20210908121014.pdf In PDF document text
    • http://studiolauramoschini.it/userfiles/files/8977137963.pdfIn PDF document text
    • http://dnepropress.net/files/file/96786452092.pdfIn PDF document text
    • http://mrhobbscoffee.com/images/uploads/file/19344336044.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/jisopofito.pdfIn PDF document text
    • http://evohome.pl/userfiles/file/segoxuxonegabegelatepixet.pdfIn PDF document text
    • https://nbc.com.vn/ckfinder/userfiles/files/dutuwilovudilusik.pdfIn PDF document text
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/86b99b577c78b565976a36ed07eac6ea/72932761155.pdfIn PDF document text
    • http://skidubravy.sk/spravca/ckfinder/userfiles/files/vulufexafagagodunu.pdfIn PDF document text
    • http://jngf.cn/files/file/7450424274.pdfIn PDF document text
    • http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/161313a96c293b---tifijutajolovonadi.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140b04956b5c---xinufam.pdfIn PDF document text
    • http://xn--p3t29jo1ed4o4xw.tw/upload/files/13732729320.pdfIn PDF document text
    • https://it-remarketing.pl/app/webroot/media/files/29473030164.pdfIn PDF document text
    • http://rinsacars.com/files/others/nuxomewidiregebaju.pdfIn PDF document text
    • http://lignumweb.com/site/webroot/uploads/files/jolifupimuzusepesineza.pdfIn PDF document text
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/161379517772b7---rixusat.pdfIn PDF document text
    • http://gsprojekt.eu/userfiles/files/togoresunelinop.pdfIn PDF document text
    • http://dmhu.eu/uploads/uplib/file/tonam.pdfIn PDF document text
    • http://gruppocreta.com/userfiles/files/mofadomunifeke.pdfIn PDF document text
    • http://jingyitech.com/uploadfile/furovazilituwisopawo.pdfIn PDF document text
    • https://gastriklandsbf.se/UserFiles/files/kologojitewas.pdfIn PDF document text
    • http://entrackintl.com/uploads/zusipolabilutikatifaroxe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=sonic+boom+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_off0000b80d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB80D 16772 bytes
SHA-256: 712c1bd3cc1aa09eea66522adda7b3d0a945298656701ac1532a0df11a364c99
font_01_sfnt_off0000e352.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE352 10304 bytes
SHA-256: f9bce85ed12055424cd8362d97545a9482e5604f2eacaba66b69a5528d74e750
font_02_sfnt_off0000fa76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA76 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1