Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac458fef7cf0961e…

MALICIOUS

PDF

82.3 KB Created: 2021-09-13 00:12:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 56d3b8408ae817811cad3a727210de21 SHA-1: aebe31dbd343364b113efbc2eb5f8b6e906bdbbc SHA-256: ac458fef7cf0961eb3edeb61e87be9d41b093807852292fd83f3bbd5e493a98a
142 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript, which is a common technique for executing malicious code. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM and the numerous unknown URLs suggest an attempt to host and distribute further malicious content. ClamAV detection and ML classification strongly indicate malicious intent, likely involving the exploitation of a PDF vulnerability to execute a payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://dotbamboo.com/file_media/file_image/file/zijosefewetiza.pdf In PDF document text
    • https://kermiradiatoriai.lt/images/files/83226591098.pdfIn PDF document text
    • https://gaadalagi.com/contents/files/tituxolika.pdfIn PDF document text
    • http://trubaopt.ru/content/file/maletalavugofenefa.pdfIn PDF document text
    • https://www.geya99.com/ckfinder/userfiles/files/25109810360.pdfIn PDF document text
    • https://rasathantrananotech.com/ckfinder/userfiles/files/pupubizemukegoxezov.pdfIn PDF document text
    • http://belovosushi.ru/files/gofovotovow.pdfIn PDF document text
    • http://vln.nl/files/file/67373801266.pdfIn PDF document text
    • https://foundationkuzmanov.com/files/jakeba.pdfIn PDF document text
    • https://smartstone.ca/userfiles/files/xijilit.pdfIn PDF document text
    • https://vinniescustoms.com/userfiles/files/60307269219.pdfIn PDF document text
    • http://acetuitioncentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161384e445f17c---19575788117.pdfIn PDF document text
    • https://inprovitecuador.com/ckfinder/userfiles/files/tuwokosukov.pdfIn PDF document text
    • http://appartementslisa.it/an3_Uploads/file/narifetitosagimebube.pdfIn PDF document text
    • https://hoavily.com/uploads/files/46023666291.pdfIn PDF document text
    • http://stellarvvv.ru/ckfinder/userfiles/files/jimegazukosej.pdfIn PDF document text
    • http://48bulls.com/js/upload/files/21555135792.pdfIn PDF document text
    • https://thaiahpa.com/flash/files/wofumerokevuzogojazirino.pdfIn PDF document text
    • http://paitoonbox.com/userfiles/files/vabulewolijinoper.pdfIn PDF document text
    • https://dailyhondaotomientay.com/upload/files/xepowawadimumilisinogufig.pdfIn PDF document text
    • http://slenderclub.cz/ckfinder/userfiles/files/47867772775.pdfIn PDF document text
    • http://cristal-in.fr/userfiles/file/xibomomelarapoxedazexage.pdfIn PDF document text
    • https://ndmoyun.com/calisma2/files/uploads/rulezesojifene.pdfIn PDF document text
    • https://ingatlansos.hu/images/userfiles/file/86957053314.pdfIn PDF document text
    • http://logiccpacma.com/ckfinder/userfiles/files/saxox.pdfIn PDF document text
    • http://yizhu580.com/ckfinder/userfiles/files/57629795654.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=mp3tube+for+iosPDF 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_off0000dd19.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD19 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f530.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF530 10444 bytes
SHA-256: 4266789e02e84d222d38b9634f0f309db837ca7b5bf97e8ff5f6d11d053d49da
font_02_sfnt_off00010cd8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CD8 18092 bytes
SHA-256: fe129ef3a750db9948e545d08cd31a15e50c47806dc96fd796ca38cd3d6dd3fd