Malicious PDF — malware analysis report

Static analysis result for SHA-256 73824308843b6b93…

MALICIOUS

PDF

87.1 KB Created: 2021-09-05 13:01:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: a5e07b837b45a704d8ce1f655e838934 SHA-1: d3991b74b72ee114b121a3ba74b501c8bac86016 SHA-256: 73824308843b6b93580bbe980d6c4df90d7af1064f0620348036974147cb96af
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to numerous URLs, many of which are hosted on compromised CMS upload storage. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the structure suggests a malicious document designed to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160b23203be640---gigoposowowodej.pdf In PDF document text
    • https://noblacklist.pro/web/img/podborky/files/39445083682.pdfIn PDF document text
    • https://isosklo.cz./uploads/memawanudividuf.pdfIn PDF document text
    • http://pm-ural.com/uploads/files/55752568266.pdfIn PDF document text
    • http://laihoawedding.com/app/webroot/upload/files/63338937742.pdfIn PDF document text
    • http://svsteinfurth.de/radsportfiles/file/sinomas.pdfIn PDF document text
    • http://annassteen.com/ckfinder/userfiles/files/sirapozenawipesikuxireja.pdfIn PDF document text
    • http://master-sign.ru/ckfinder/userfiles/files/xoxidaki.pdfIn PDF document text
    • http://espressoperfetto.nl/app/webroot/files/userfiles/files/11141336093.pdfIn PDF document text
    • https://www.rapn.ru/ckfinder/userfiles/files/37984039304.pdfIn PDF document text
    • http://h-st.nl/bestanden/files/43008058576.pdfIn PDF document text
    • http://sapientgenerator.ru/files/userfiles/files/duzegumelusisesesefo.pdfIn PDF document text
    • http://traditionsradio.com/wp-content/plugins/super-forms/uploads/php/files/qsuqbkfjfpaefr948tt2m6l9f2/34405825163.pdfIn PDF document text
    • http://diagonal.org.ar/wp-content/plugins/formcraft/file-upload/server/content/files/1609236769ad03---vozotolekuzexusexewom.pdfIn PDF document text
    • http://ontheedgeofnow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac2885846a7---27194247994.pdfIn PDF document text
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/160945c519854e---43176559341.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/160805d7ccaf20---7566337722.pdfIn PDF document text
    • http://ristoranteyuri2.com/userfiles/file/46542562430.pdfIn PDF document text
    • https://hijaustabilo.com/contents/files/67974957486.pdfIn PDF document text
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1da489bb3e---kuvagewobofetumapirur.pdfIn PDF document text
    • http://donaldnathanlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/96509715846.pdfIn PDF document text
    • http://ozdesignhouse.com/app/webroot/uploads/files/tedivazura.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609e9ec60766d---kijodariz.pdfIn PDF document text
    • https://chaletsuenodesol.de/files/vuwegan.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=biblical+investment+strategies+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_off0000ef77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF77 11100 bytes
SHA-256: b68c1d165911402129f92059c62b4dd6b212a31684f32fdbab735c835d22ce57
font_01_sfnt_off000108fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108FA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001210c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1210C 17708 bytes
SHA-256: 742719fcbecf40c3a75b9f8e030987b916a22558f17fe089632434792bbae805