Malicious PDF — malware analysis report

Static analysis result for SHA-256 43c18e46686a3918…

MALICIOUS

PDF

80.8 KB Created: 2021-09-04 10:23:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 554e9f7e095d30098645d1b11b267fd3 SHA-1: f727e90717c6d5028fd491c05e85546c1cbf3b58 SHA-256: 43c18e46686a3918f5b46069abfdd27a859d3a31a0cf8855fbe336bd55385428
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting it functions as a link farm. The presence of these links, combined with the PDF structure, points towards a phishing or malware distribution campaign, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://yourhealthyanswer.com/ckfinder/userfiles/files/97693146349.pdf In PDF document text
    • https://dichvuketoanvn.org/uploads/files/30407567000.pdfIn PDF document text
    • https://bodwellassociates.com/wp-content/plugins/super-forms/uploads/php/files/c12b58022fc36b033ec4e09eaa60a355/wonusejitixu.pdfIn PDF document text
    • http://mirandatutoringcentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160818f096e08f---javezojukanufapokopinakub.pdfIn PDF document text
    • http://archiw.bibliotekalesmierz.eu/img/upload/files/rasarusimenivotodorono.pdfIn PDF document text
    • https://best-label.com/upload/files/23558316052.pdfIn PDF document text
    • https://marksiegeldds.com/wp-content/plugins/super-forms/uploads/php/files/9a2d2d74264ddb46a1a226c5e597f5a0/80885326578.pdfIn PDF document text
    • http://seksdagen.nl/userfiles/file/73151454341.pdfIn PDF document text
    • http://biurod9.pl/public/userfiles/file/wonoxijisumugemuso.pdfIn PDF document text
    • https://cor.org.ar/wp-content/plugins/super-forms/uploads/php/files/gbei2qmfd13h18dth72cv2p7aq/56307929998.pdfIn PDF document text
    • https://doitsolutions.co/wp-content/plugins/super-forms/uploads/php/files/1c49d75034b07a57f1c834a45804d384/nutazamafomowi.pdfIn PDF document text
    • http://sunrui-ti.com/d/files/lurarumuz.pdfIn PDF document text
    • http://wypelnienia.kratex.pl/wp-content/plugins/super-forms/uploads/php/files/542a0d1cc1da296c952be1b2558061fc/30932183055.pdfIn PDF document text
    • http://hogan1973.com/clients/d/d4/d4eda5e2427b34f3a15374adde9a77da/File/devade.pdfIn PDF document text
    • http://cheapneasytrafficschool.com/CheapNEasyTrafficSchool/pa/trainstation/uploads/image/file/82183712971.pdfIn PDF document text
    • http://nedirajtebosnu.net/userfiles/file/30044428905.pdfIn PDF document text
    • http://deborahkay.com/ckfinder/userfiles/files/24917840551.pdfIn PDF document text
    • https://robinio.de/wp-content/plugins/super-forms/uploads/php/files/6jokgiqhkuda62omrsdsde6mh7/21545918529.pdfIn PDF document text
    • http://nwatchonline.org/userfiles/file/18915183635.pdfIn PDF document text
    • https://qfse.co/images/uploaded_files/ckfinder/files/1626517591_2db6480ca2.pdfIn PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/ujjtrmcobunoko0f7lad0cc3ih/21053533714.pdfIn PDF document text
    • https://marigabung.com/contents//files/bubufewedilujenezemanome.pdfIn PDF document text
    • https://daiichigroup.net/uploads/news_file/65770859847.pdfIn PDF document text
    • https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b12e297ada---zuvugatujo.pdfIn PDF document text
    • https://elitestrategyglobal.com/wp-content/plugins/super-forms/uploads/php/files/d63d863405a8c8b770f7857202bcbc05/zifefuwik.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=is+it+love+or+is+it+addiction+slaa+pdfPDF 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_off0000d796.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD796 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000efad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFAD 10628 bytes
SHA-256: 527c12153ee02c6add3e560f9ceaeb6772e6930d84469367ef325a1e975eba1b
font_02_sfnt_off0001081e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1081E 17620 bytes
SHA-256: 159892491b007196ab363e8a6e5a174638782023ef554bd2f8ec78a975ab6140