Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f636e2905c30866…

MALICIOUS

PDF

81.6 KB Created: 2021-09-20 01:19:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 3663764ff63bd256b9327c44022a1e3d SHA-1: e2985a9ba444a381d5aa558d57c9a32ea890e4fc SHA-256: 3f636e2905c308662745b0269fe88a56577bb0ed8b8f08caa6f0d50444fde370
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by multiple heuristics as containing a link farm pointing to compromised or disposable hosting. The ML classifier and ClamAV also identified it as malicious, specifically as a phishing trojan. The embedded URLs suggest an attempt to redirect users to potentially harmful sites, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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 https://openkomm.yussfone-crm.com/userfiles/file/gulexexutuxos.pdf In PDF document text
    • http://ledspectrumthai.com/ckfinder/userfiles/files/93238672173.pdfIn PDF document text
    • http://sendedianqi.com/upload_fck/file/2021-9-11/20210911201617628852.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/161350869af5b6---13663403954.pdfIn PDF document text
    • http://cocoal.com/uploads/file/zupagavawimelos.pdfIn PDF document text
    • http://ipcmanpower.com/admin/style/images/userfiles/file/65294651310.pdfIn PDF document text
    • https://beaufortbond.com/wp-content/plugins/super-forms/uploads/php/files/a2b9988f9365e4f95137241a7511f4e6/19595312760.pdfIn PDF document text
    • http://emaaravm.net/upload/files/zaboje.pdfIn PDF document text
    • http://acsalma.hu/userfiles/files/vomagugegideso.pdfIn PDF document text
    • http://resulgame.com/calisma2/files/uploads/46925434831.pdfIn PDF document text
    • http://planao.com/ckfinder/userfiles/files/vapeziwimiwogavasap.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/6df0b3a5c44ccb0664c57ed9e104c380/43544062562.pdfIn PDF document text
    • http://rileyillustration.com/images/agency/files/3539566212.pdfIn PDF document text
    • http://popmetre.com/news/files/96038767462.pdfIn PDF document text
    • http://studiolegaletrotta.eu/userfiles/files/tibegusosakusedanewobosa.pdfIn PDF document text
    • http://manhtreminhduc.com/webroot/img/files/zepaw.pdfIn PDF document text
    • https://buyafranchise.org/files/files/53614268370.pdfIn PDF document text
    • http://hnkingdee.cn/Files/file/20219333626.pdfIn PDF document text
    • https://jyapa.com/jhuoyue/uploadfiles/zumipabafo.pdfIn PDF document text
    • https://onlineadda.organicemall.com/ckfinder/userfiles/files/540001051.pdfIn PDF document text
    • http://aedwea.com/upload/foto/50679637030.pdfIn PDF document text
    • http://hulstcustoms.ru/uploads/files/digoroneninupitobukukevi.pdfIn PDF document text
    • http://timatey.kz/wp-content/plugins/super-forms/uploads/php/files/u4gqkq0i9ptkgo2a1o7d6kmqh2/82860514858.pdfIn PDF document text
    • https://unovosti.tv/ckfinder/userfiles/files/pitug.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=android+mediacontroller+custom+layoutPDF 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_off0000d910.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD910 18040 bytes
SHA-256: bd3a2f6a05d6e15c6c81450ba77b4a1fbabf5d7d1c4e2a6cd2a90c7de25b42c6
font_01_sfnt_off0001084a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1084A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012061.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12061 10724 bytes
SHA-256: 8ffb3488f05896653f2b64bb167e3f653b4a8bf4473105ed221ccf55723df110