Malicious PDF — malware analysis report

Static analysis result for SHA-256 9af88666367effb2…

MALICIOUS

PDF

80.9 KB Created: 2021-09-14 18:24:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 97b758c4f50f33081aa4ddaf2b469bb2 SHA-1: f117afbbb79fb7dc2722bf8cdab7d58056f34904 SHA-256: 9af88666367effb299e08610a5767b13ef43d78d553c4e96a5dba1911f3fc457
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which appear to be part of a link farm designed to obscure the ultimate destination. One prominent URL, 'https://synerhu.ru/uplcv?utm_term=play+services+download', suggests a lure for users seeking software downloads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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 https://synerhu.ru/uplcv?utm_term=play+services+download PDF link annotation
    • http://www.scenekunstskolen-efteruddannelsen.dk/ckfinder/userfiles/files/zunowake.pdfIn PDF document text
    • http://kapelski.pl/userfiles/file/balotorewukazi.pdfIn PDF document text
    • https://bharatiyabhashaparishad.org/ckfinder/userfiles/files/14929971208.pdfIn PDF document text
    • http://tahyuh.com/uploads/files/202109130825323710.pdfIn PDF document text
    • http://findacommodity.com/upload/file/tikinusowanukizimojakov.pdfIn PDF document text
    • https://samsungdvm.net/upload/ckfinder/files/38689195874.pdfIn PDF document text
    • http://highendschmiede.de/highendfiles/file/molejababufizipevage.pdfIn PDF document text
    • http://maremio.ru/admin/ckfinder/userfiles/files/gupojirez.pdfIn PDF document text
    • http://centromedicoveterinarioadda.com/userfiles/files/79899520233.pdfIn PDF document text
    • http://thermocomfort.ca/userfiles/file/92743531134.pdfIn PDF document text
    • https://ldcpc.com/ckfinder/userfiles/files/47916326611.pdfIn PDF document text
    • https://anne-berger.de/sites/anne-berger.de/files/fkcfile/21279533043.pdfIn PDF document text
    • https://autopsrus.aerovents.com/ckfinder/userfiles/files/52409706546.pdfIn PDF document text
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/1612eb213eba65---56791009128.pdfIn PDF document text
    • http://xn--80aiddhbkcq5bcaz.xn--p1ai/upload/files/baruvesurajojire.pdfIn PDF document text
    • https://lajovisena.com/gallery/file/kotogubiwefexuwov.pdfIn PDF document text
    • https://ckfinder.pamlskovnik.cz/ckfinder/userfiles/files/49961516168.pdfIn PDF document text
    • https://hizlipin.com/calisma2/files/uploads/zonowazulekabawaduwe.pdfIn PDF document text
    • http://tagsu.com/attachments/fckattachments/file/xujezaz.pdfIn PDF document text
    • https://forumhotel.by/wp-content/plugins/super-forms/uploads/php/files/jfgenptj8njvipkqht70ttp6f3/danotonofojo.pdfIn PDF document text
    • http://toshiteriyakiburien.com/uploads/files/jefijepo.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_off0000d9d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9D7 17384 bytes
SHA-256: e1928341a9fff375c7e70201a7a8de660e220701de7757f8dfaf466d33daaaba
font_01_sfnt_off0001066e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1066E 10532 bytes
SHA-256: 5dd269f1392c1295d5c65da8c20b3ddb6f212ff91a163f932d7b9239b42ba445
font_02_sfnt_off00011ea1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EA1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1