Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4cba7cd4ac4eaf2…

MALICIOUS

PDF

71.2 KB Created: 2021-09-25 20:19:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: a1846d343e84fd0b78d37b8cc8499441 SHA-1: 1874a12bdd50fef915b21c290b2c452de99b55c6 SHA-256: a4cba7cd4ac4eaf23c3a458fb5d26efd9913a5450bcbf0c8c811b8b5415a70b3
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for delivering malicious content. The PDF also contains numerous external URIs, many of which are hosted on disposable domains, suggesting a phishing or malware distribution campaign. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9909

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
  • 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 http://hijoin.hu/editor_up/36214771363.pdf In PDF document text
    • https://mbamantra.com/ci/userfiles/files/35700770828.pdfIn PDF document text
    • http://vinaktv.com/storage/ckfinder/files/99041495849.pdfIn PDF document text
    • http://ozcetinler.com/userfiles/file/53077385718.pdfIn PDF document text
    • http://cameradungphat.com/uploads/files/80507648177.pdfIn PDF document text
    • https://baatco.com/ckfinder/userfiles/files/69694611145.pdfIn PDF document text
    • http://feuerwehrobrigheim.de/upload/files/valega.pdfIn PDF document text
    • http://ristorantebiscione.com/userfiles/files/rinikupomapiwumufatuj.pdfIn PDF document text
    • https://gulf-rope.com/images/bulk_images/files/wosawinuz.pdfIn PDF document text
    • https://immsac.pe/sgi_userfiles/userfiles/files/gusebede.pdfIn PDF document text
    • https://remini.hu/userfiles/file/xufuw.pdfIn PDF document text
    • https://riminabda.sk/userfiles/file/61926143307.pdfIn PDF document text
    • http://hattingtoemrerogsnedker.dk/userfiles/file/lonivurovevagemakawem.pdfIn PDF document text
    • https://tefen67.com/userfiles/files/24179843366.pdfIn PDF document text
    • http://brmxn.com/userfiles/file/20210910191408_df38ib.pdfIn PDF document text
    • https://serihosting.com/calisma2/files/uploads/somapasadinuvelujeburidoz.pdfIn PDF document text
    • http://autostyle-japan.com/js/upload/files/17175979380.pdfIn PDF document text
    • http://fullcolorspandoeken.nl/userfiles/file/42774144231.pdfIn PDF document text
    • http://instit.ac/ckfinder/userfiles/files/zazifomowowunejoveso.pdfIn PDF document text
    • https://thietbivesinhsonhoa.com/webroot/img/files/70264845722.pdfIn PDF document text
    • https://bibonatura.com/ckfinder/userfiles/files/18298378126.pdfIn PDF document text
    • http://evola.it/userfiles/files/92576849769.pdfIn PDF document text
    • http://www.pethouse.es/ckfinder/userfiles/files/tokosuporanumotibopuzejet.pdfIn PDF document text
    • https://marathonblainville.com/userfiles/files/82351612252.pdfIn PDF document text
    • https://monarchwinemerchants.com/wp-content/plugins/super-forms/uploads/php/files/218051c4316783a85f17fdedd5c2df97/70446866823.pdfIn PDF document text
    • https://truckforceone.com/upload/editor/file/nudeperovudilinupabuni.pdfIn PDF document text
    • http://exmar.it/foto_fck/file/47793413598.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=english+hot+movies+online+watchPDF 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_off0000b4ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4CA 15824 bytes
SHA-256: 4e96f3ed21ef141e32c4788f315de72b99c40e7892d297e66899ff1a7086c681
font_01_sfnt_off0000dca4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCA4 10712 bytes
SHA-256: 96264986580b1289cd6ee17244323c4f03dc42b074722cf01fa134d23479d119
font_02_sfnt_off0000f51f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF51F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1