Malicious PDF — malware analysis report

Static analysis result for SHA-256 23413f889ac7048a…

MALICIOUS

PDF

72.7 KB Created: 2021-09-24 12:47:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 0c9b8a8deb43779eec523b3f81b947a1 SHA-1: 74c6fe58a6f538b96dc4df0d3c8e8e612ef7fe30 SHA-256: 23413f889ac7048af3e328d007bfa5f8cdff1ae61404e9736f303014d3ee5801
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged as malicious by ClamAV and an ML classifier. It contains an embedded JavaScript stream and numerous external URIs, many of which are hosted on disposable domains and appear to be part of a link farm. The embedded JavaScript and the nature of the URLs suggest an attempt to redirect users to malicious websites, likely for phishing or to download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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 https://crysiq.ru/uplcv?utm_term=get+photos+off+android+phone PDF link annotation
    • http://villkasz.hu/editor_up/tidalegezopifijuxa.pdfIn PDF document text
    • http://blpest.com/UserFiles/file/fojedusim.pdfIn PDF document text
    • http://bienchidan.org/uploads/files/gavuperemi.pdfIn PDF document text
    • http://remobudostol.pl/pliki/15920257856.pdfIn PDF document text
    • http://misr-consult.com/userfiles/file/bujasedulisis.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/31543355375.pdfIn PDF document text
    • http://mundori.com/js/ckfinder/userfiles/files/24132296725.pdfIn PDF document text
    • http://qianlong99.org/ckfinder/userfiles/files/modorimari.pdfIn PDF document text
    • http://ipsaix.com/ckeditor/ckfinder/userfiles/files/gebafutedaligitefap.pdfIn PDF document text
    • http://yonseri.org/userfiles/files/49559192924.pdfIn PDF document text
    • http://lexxyin.net/files/fckeditor/file/musizuwoponoxorupezi.pdfIn PDF document text
    • https://somogyplusz.hu/files/waxowezoxise.pdfIn PDF document text
    • https://holcom-wd.holcom.vn/webroot/img/files/bisonivuwes.pdfIn PDF document text
    • http://ucinnovation.ru/admin/ckfinder/userfiles/files/sowiwu.pdfIn PDF document text
    • https://xn--80aaijzh9b.xn--90ae/documents/file/mosogokixabesubuduv.pdfIn PDF document text
    • http://eperon-kochersberg.com/img_db/zomobafewapagufazexirata.pdfIn PDF document text
    • http://aroma-es.site/yamituki-n/uploads/files/53651247691.pdfIn PDF document text
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1613ab3fe17519---bijoxorubur.pdfIn PDF document text
    • https://myarchitect.es/ckfinder/userfiles/files/66349638767.pdfIn PDF document text
    • https://www.speeddating.lt/speeddating/ckfinder/userfiles/files/nevojesek.pdfIn PDF document text
    • https://ecoinkworld.com/wp-content/plugins/super-forms/uploads/php/files/e4098662562314b7dddec3481417e6dc/85392574760.pdfIn PDF document text
    • https://www.hasmow.com.au/application/third_party/ckfinder/userfiles/files/8795760492.pdfIn PDF document text
    • http://art-wonders.com/ckeditor/ckfinder/core/connector/php/uploads/files/lodurodire.pdfIn PDF document text
    • http://aaaexpressheating.com/userfiles/file/30324204537.pdfIn PDF document text
    • http://joyerialaplaza.com/ckfinder/userfiles/files/pivutenudubamixelufo.pdfIn PDF document text
    • https://mcq-exambd.com/app/webroot/ckfinder/userfiles/files/86942032314.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_off0000b72f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB72F 10588 bytes
SHA-256: 925ac7b785cde304f5f813ff4796992897876b0e83b42fc00ec32ccbdf5d24c9
font_01_sfnt_off0000cf56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF56 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e768.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE768 17960 bytes
SHA-256: 7e63ada268fa341e2a9f396805b9364142287bd569e5b16f1d673f71dced34c5