Malicious PDF — malware analysis report

Static analysis result for SHA-256 850fb05d700af2bd…

MALICIOUS

PDF

85.4 KB Created: 2021-09-17 09:15:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 27178ce1072a72f49803131048025182 SHA-1: 254897bb43aa69aa0fd2a02b99d6cb1975112741 SHA-256: 850fb05d700af2bd688df4c287eff3edde93b8426fb8d83298a85c6c4a8fcb2e
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics indicate it functions as a link farm, directing users to multiple compromised websites, including those hosted on disposable domains and potentially compromised CMS uploads. The primary purpose appears to be directing users to malicious or phishing sites, aligning with a spearphishing attachment attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://www.themixchange.com/userfiles/files/gifexa.pdf In PDF document text
    • http://think6.net/ckfinder/userfiles/files/20210905232507.pdfIn PDF document text
    • http://www.celso.org/download/47648411313.pdfIn PDF document text
    • https://delcinfo.ru/img/files/files/90595655755.pdfIn PDF document text
    • http://kangmeideyiliao.com/uploadfile/file///2021091402172811.pdfIn PDF document text
    • https://hgindustrial.eu/userfiles/files/70282295943.pdfIn PDF document text
    • http://asesoriagarpe.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cfb9f9cfda---27141722346.pdfIn PDF document text
    • http://nickels.design/ckfinder/userfiles/files/tokaxusu.pdfIn PDF document text
    • http://www.thebetterinsurance.com/wp-content/plugins/formcraft/file-upload/server/content/files/161383c8b12a33---nidizuperi.pdfIn PDF document text
    • http://facilitymanagementassociates.com/survey/userfiles/files/2263813752.pdfIn PDF document text
    • http://yearbookplus.com/uploads/ckfinder/files/14901517518.pdfIn PDF document text
    • http://terralis.net/catalogue_dynamique/file/jegozojadipurotimuxojubeg.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/161345f573d7f8---92247412913.pdfIn PDF document text
    • https://truckforceone.eu/upload/editor/file/3312143771.pdfIn PDF document text
    • http://armanetti.com/images/53496450596.pdfIn PDF document text
    • http://herfon-machinery.com/images/ckfinder/files/20210903131326.pdfIn PDF document text
    • http://jacsonsfurniture.com/userfiles/file/dobutovasa.pdfIn PDF document text
    • https://dejavuruse.com/userfiles/file/16096625029.pdfIn PDF document text
    • http://allgeology.ru/ckfinder/userfiles/files/nojaxuvifotuvunimo.pdfIn PDF document text
    • https://egc.ecrom.work/syo/files/nuzugozedafagufagid.pdfIn PDF document text
    • http://sinsg.com/files/fckeditor/file/berobumawelopizefexikepe.pdfIn PDF document text
    • http://patrick-vallot.com/upload/files/naxebakike.pdfIn PDF document text
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613eca83718d1---wugukedepuxovo.pdfIn PDF document text
    • https://stgeorgedentalcare.in/ckfinder/userfiles/files/mapegapisifozukewomobef.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=best+browser+app+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_off0000eac8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAC8 17188 bytes
SHA-256: 4b231d4aee92ad9b25c1ee541ef3a39360ede27318788a3dbcb64e8617061c3f
font_01_sfnt_off00011738.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11738 10724 bytes
SHA-256: ed8ba023906d840341d5642af3f7352606812d5511533430c20968725b70769c
font_02_sfnt_off00012fe5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12FE5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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