Malicious PDF — malware analysis report

Static analysis result for SHA-256 161efb0edb406e39…

MALICIOUS

PDF

74.5 KB Created: 2021-09-10 13:43:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: cb4e95c4a509b0f177623522a38f1821 SHA-1: 0a838bd2943fc8943b6acd36a790ff9945afe331 SHA-256: 161efb0edb406e39b1c249d46af6833df3ccb170e0c4698ff522e3a2b2aac895
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a large number of external URIs, many of which are part of a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The embedded JavaScript is likely used to facilitate the redirection to these malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://huntic.ru/uplcv?utm_term=archero+mod+apk+android+1 PDF link annotation
    • https://eurosan.pl/user_images/file/notolorawu.pdfIn PDF document text
    • http://crescentcarpets.com/userfiles/file/77426809995.pdfIn PDF document text
    • http://agisma.ru/files/pages/files/folusawukoz.pdfIn PDF document text
    • https://www.hmgfinance.com/ckfinder/userfiles/files/xadefitevalikanad.pdfIn PDF document text
    • http://mh-gartengestaltung.de/userfiles/file/63975153506.pdfIn PDF document text
    • http://tjsijiqing.com/ckfinder/userfiles/files/2021/0908/b94718ec454cd2c2e549348e94b3b92e.pdfIn PDF document text
    • http://maezawa-jidousha.com/js/upload/files/43523905330.pdfIn PDF document text
    • https://alrukn.co/userfiles/files/korawakafujazefaxajekinuw.pdfIn PDF document text
    • http://thedewakohchang.com/image/upload/File/5447341840.pdfIn PDF document text
    • https://alutat.com/data/file/xelofowiw.pdfIn PDF document text
    • http://ikhmongol.mn/ckfinder/userfiles/files/vezipamalobozo.pdfIn PDF document text
    • http://auswallendorf.de/userfiles/file/4501213720.pdfIn PDF document text
    • http://pes.edu.mn/ckfinder/userfiles/files/36045589113.pdfIn PDF document text
    • http://pm-property.pl/userfiles/file/vegumefu.pdfIn PDF document text
    • http://partnercable.hu/files/12518396397.pdfIn PDF document text
    • http://rts-3.ru/upload/files/febanikiworufet.pdfIn PDF document text
    • http://sanraimundo.cl/dyn/uploads/file/87972508237.pdfIn PDF document text
    • https://htapigroup3.com/contents/files/mibunubevelu.pdfIn PDF document text
    • http://gfzgt.ch/upload/file/welaze.pdfIn PDF document text
    • http://ryyw.com/upload/files/2021/09/202109030036412305.pdfIn PDF document text
    • http://aelma.com/sites/default/userfiles/file/95178317447.pdfIn PDF document text
    • http://www.megasaludips.com/wp-content/plugins/formcraft/file-upload/server/content/files/161388f54ce462---jexemujudanevesawigimi.pdfIn PDF document text
    • http://axiomestates.com/userfiles/file/84270000092.pdfIn PDF document text
    • http://japanbizkorea.com/userData/ebizro_board/file/mosuweruvaguli.pdfIn PDF document text
    • http://newshop.jp/archive/file/55277957532.pdfIn PDF document text
    • http://gfzgt.ch/upload/file/juvaliweferuwu.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_off0000c1ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1CA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d9e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9E1 10592 bytes
SHA-256: eb2aa8090b93c2e1281ced7804c931d5a61d6d6c1ec13bbb15df47787e4940cc
font_02_sfnt_off0000f1e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1E3 16416 bytes
SHA-256: a056fc1b7361188bc5ad71cd126b6493310eb57775b57bacac490f8799ecf8b9