Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8bf8818b0e160fc…

MALICIOUS

PDF

82.0 KB Created: 2021-09-14 17:55:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 37b8b452d93e5389e2dd3524dad670db SHA-1: 73422165c41bc8ae86dc74a67ff02e912abdd415 SHA-256: c8bf8818b0e160fc4c21d2699eb50e7bed24667adfb9670754edc9395ccea76a
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to disposable hosting and form a link farm, suggesting a phishing or redirection attempt. The PDF's structure and the presence of embedded URLs indicate it's likely part of a spearphishing campaign designed to lead users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • 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.
  • 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://hotelrefah4ter.ir/basefile/hotelrefah4terir/files/86111308999.pdf In PDF document text
    • http://imhang.com/fckeditor/userfiles/image/kepob.pdfIn PDF document text
    • http://kibunajcc.com/ckfinder/userfiles/files/32506304702.pdfIn PDF document text
    • http://elosc.com/upFile/file///ITX202109011857065456.pdfIn PDF document text
    • http://leadingedgecorporate.com/user_images/file/21676396414.pdfIn PDF document text
    • https://namdolove.com/FileData/ckfinder/files/20210909_27D7350BD1FE1ED4.pdfIn PDF document text
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/1613401ac686b7---1476544279.pdfIn PDF document text
    • https://naveenent.com/administrator/imagetemp/file/71233151329.pdfIn PDF document text
    • http://baschin-heizung.de/meineBilderAlbertGrundschule/file/nopizo.pdfIn PDF document text
    • http://bestbelly.org/content/files/files/44474814389.pdfIn PDF document text
    • http://harnettcountyhba.com/userfiles/file/rafoferinesanu.pdfIn PDF document text
    • http://doorsatyrau.com/ckfinder/userfiles/files/46396829862.pdfIn PDF document text
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f05c064191---12495521363.pdfIn PDF document text
    • http://xdata.pl/app/webroot/img/ckf/files/21153427991.pdfIn PDF document text
    • http://regmac.net/userfiles/files/14934894943.pdfIn PDF document text
    • http://geerhannutpourreussir.be/docs/upload/files/92226475336.pdfIn PDF document text
    • http://streathamtaxi.com/survey/userfiles/files/77390578493.pdfIn PDF document text
    • https://robertmatzuzi-massagetherapist.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16132615e87730---bimemago.pdfIn PDF document text
    • http://nemeckystrakac.sk/editor_uploads/files/juketujexetobed.pdfIn PDF document text
    • http://cssh.es/img/file/76751835374.pdfIn PDF document text
    • http://tsnpharma.com/upload/files/ferudinetubepa.pdfIn PDF document text
    • http://epodhajska.eu/UserFiles/File/48387486910.pdfIn PDF document text
    • https://ksi-system.pl/editorfiles/file/kamonisutovelalidas.pdfIn PDF document text
    • http://wksystems.net/HotelEstimator/userfiles/file/21723721836.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=periodic+table+pdf+with+electronegativityPDF 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_off0000d95f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD95F 17948 bytes
SHA-256: 5c4e2a120496715aa648afa1bf15d940d8297260599e98488ca291ba1fc0efd0
font_01_sfnt_off00010852.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10852 11136 bytes
SHA-256: dd65bef51037ebacd56245225dd9674cde87591ccbc1349ae6e405c5be556235
font_02_sfnt_off000121e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121E1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1