Malicious PDF — malware analysis report

Static analysis result for SHA-256 dec8dcb1d7b20dc4…

MALICIOUS

PDF

70.7 KB Created: 2021-09-27 06:58:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: b9c6eae2d4c24a2a426286fd0ffd07bd SHA-1: 74df486bbf147f292263c5c47b72a58abbca7ee3 SHA-256: dec8dcb1d7b20dc4dda186ee1fa071418e732ea85b8a91680319508561c3d54c
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which are part of a link farm hosted on compromised or disposable domains. The presence of JavaScript and the link farm structure strongly suggest an intent to redirect users to malicious sites, likely for phishing or to download further malware. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://inwebjor.ru/uplcv?utm_term=plants+vs+zombie+2+apk+hack PDF link annotation
    • http://tourbusan.net/FileData/ckfinder/files/20210913_52062D2100F85316.pdfIn PDF document text
    • http://herve-coiffure.ci/files/29980877745.pdfIn PDF document text
    • http://haki.vn/uploads/files/sebikuba.pdfIn PDF document text
    • http://geology.ie/wp-content/plugins/formcraft/file-upload/server/content/files/1613729d23615f---16665965150.pdfIn PDF document text
    • https://lawweb.info/mycms/admin/userfiles/file/nixexuxaloxo.pdfIn PDF document text
    • http://serextion2006.com/js/upload/files/xokidifediwititepona.pdfIn PDF document text
    • http://www.gamylai.vn/uploads/files/viwebidi.pdfIn PDF document text
    • https://emenu.hu/editor_up/49777417729.pdfIn PDF document text
    • https://www.zaantraining.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16133b9f6defc3---82143603468.pdfIn PDF document text
    • https://www.jaegeraviation.com/ckfinder/userfiles/files/kenageseninugafis.pdfIn PDF document text
    • https://elicopter-de-inchiriat.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613760851b5f3---21341124428.pdfIn PDF document text
    • http://xn--hy1bt45apoap01a.net/jangheung/userfiles/file/dopolusog.pdfIn PDF document text
    • http://www.gametimecatering.com/wp-content/plugins/formcraft/file-upload/server/content/files/16145c4c1e014d---76299715821.pdfIn PDF document text
    • https://semut73.com/contents/files/lunofevaxinofokolaki.pdfIn PDF document text
    • https://aildf.in/userfiles/file/5939590464.pdfIn PDF document text
    • https://ukmriptek.org/codeIgniter-hmvc/userfiles/files/sexufipi.pdfIn PDF document text
    • http://chipgene.com/image/files/20210922_083319.pdfIn PDF document text
    • http://telefoonindex.nl/images/uploads/8872057302.pdfIn PDF document text
    • http://trineckevzdelavani.cz/webpagebuilder/ckfinder/userfiles/files/50587302643.pdfIn PDF document text
    • http://mzch.pl/userfiles/file/55294117235.pdfIn PDF document text
    • http://contrast.no/ckfinder/userfiles/files/78159299732.pdfIn PDF document text
    • http://telegid.tv/userfiles/files/bonivuvad.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_off0000b0d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0D6 16288 bytes
SHA-256: 34c16c5024ccda622c6b305051a11c19c32d2dd1d2de9df6f59ae1643811fcf6
font_01_sfnt_off0000da40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA40 11020 bytes
SHA-256: 0e9f4913c437b6118ed6553c2f4167c3d3fdbee0aea2608a1143e6bb96b5e0df
font_02_sfnt_off0000f398.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF398 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1