Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb8cdb72697373c9…

MALICIOUS

PDF

85.1 KB Created: 2021-09-13 23:49:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 811919a537859b1c8ab48fbba92c2a7e SHA-1: 9106456dd0248aadb6a9385bcaf64ffa9e300178 SHA-256: cb8cdb72697373c9e27a53e7c67c8daa70e56831abd13942f57e0633dd21440d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high probability of malicious intent. The PDF contains numerous embedded URLs, many of which point to disposable hosting and are structured as link farms, a common tactic for phishing or distributing further malware. The presence of these links suggests the document's primary purpose is to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 5

  • 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.
  • 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://wastran.ru/uplcv?utm_term=fnaf+4+demo+free+play PDF link annotation
    • https://bosgo.mn/uploads/files/winotepunivow.pdfIn PDF document text
    • http://clainvest.pl/userfiles/file/39123565281.pdfIn PDF document text
    • https://sunridgecorp.com/uploads/files/202109031029526062.pdfIn PDF document text
    • https://stoneappeal.in/FCKeditor/file/65421527224.pdfIn PDF document text
    • http://quatangsongvan.com/hinhanh_fckeditor/file/2669066066.pdfIn PDF document text
    • http://smolensk-bakaleya.ru/userfiles/file/tasilajeboliwekogodijazo.pdfIn PDF document text
    • http://cl-pub.com/files/files/pimutaruw.pdfIn PDF document text
    • https://hinodanang.com/uploads/image/files/26125480238.pdfIn PDF document text
    • http://e-motyle.natura2000.pl/imgturysta/files/95514506148.pdfIn PDF document text
    • http://pataibicaj.hu/userfiles/file/nuxuzosike.pdfIn PDF document text
    • http://huile-de-nigelle.info/userfiles/file/35488479970.pdfIn PDF document text
    • http://ricettebiagi.it/uploads/assets/file/96863276886.pdfIn PDF document text
    • https://echipamente-scule.ro/userfiles/file/kumedimad.pdfIn PDF document text
    • https://happyfun.tw/uploads/files/202109091247491976.pdfIn PDF document text
    • https://art4you.sk/editor_uploads/system/files/66718299731.pdfIn PDF document text
    • http://prunay-en-yvelines.fr/ckfinder/userfiles/files/27987091593.pdfIn PDF document text
    • http://wych123.com/upload/files/bimogukaveza.pdfIn PDF document text
    • http://security-m.jp/tool/images/file/12910384054.pdfIn PDF document text
    • http://1-sanya.com/blog_images/blog_/file/53016916656.pdfIn PDF document text
    • http://ticketsperiodico.com/galeria/files/51684287799.pdfIn PDF document text
    • http://universalthailand.com/images/uploads/ckfinder/files/tijuweganupomirujazig.pdfIn PDF document text
    • http://emailreceptionist.net/userfiles/file/61795598621.pdfIn PDF document text
    • http://ediljolli.com/userfiles/files/dujusujejetaredajeni.pdfIn PDF document text
    • http://yomamasushitogo.com/uploads/files/tedizawulebikewifegawufa.pdfIn PDF document text
    • http://saint-party.com/media/file/biviwiziw.pdfIn PDF document text
    • https://iamtimeshare.com/userfiles/file/9879251141.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_off0000e6c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6C7 18440 bytes
SHA-256: 17e669ff3c8127eede143fa140d17781d105cc24c5d267e32658be237d6ff804
font_01_sfnt_off000116f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116F1 10468 bytes
SHA-256: fe3b8c5c174434bfaf4b1eb9a5f17588fe5f7817235528115d2d71358f1d61de
font_02_sfnt_off00012eb1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12EB1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1