Malicious PDF — malware analysis report

Static analysis result for SHA-256 8739ea5723709e15…

MALICIOUS

PDF

81.6 KB Created: 2021-10-07 09:41:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: af2bee90b59638f9f10ff462d63ad1f3 SHA-1: 1ad79b5a269c3fdd3ec7465514f178523f3496f5 SHA-256: 8739ea5723709e15b9c8e3aaabaf691b0de9c91d0ca942bc4bf921de71166fac
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 point to disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is a common technique for exploiting PDF vulnerabilities or redirecting users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://medvor.ru/uplcv?utm_term=self+introduction+paragraph PDF link annotation
    • https://ardiinerkh.mn/uploads/userfiles/files/tuwubezo.pdfIn PDF document text
    • http://studiophotosfashion.it/userfiles/files/zoxomo.pdfIn PDF document text
    • http://quimis.org/js/ckfinder/userfiles/files/13363756405.pdfIn PDF document text
    • http://dobrasekacka.cz/userfiles/file/zojivemobugabi.pdfIn PDF document text
    • http://silverspringabw.com/uploads/files/jobapalogofuvejuw.pdfIn PDF document text
    • http://chipgene.com/image/files/20210916_012145.pdfIn PDF document text
    • http://kgmda.com/upload/files/divolixofid.pdfIn PDF document text
    • http://cyclad.org/UserFiles/file/noselonere.pdfIn PDF document text
    • https://www.pension-chevaux-haras-gabereau.fr/ckfinder/userfiles/files/kamotexamerolosoxibefeme.pdfIn PDF document text
    • http://furkansigorta.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16145b6d9235f7---75502485673.pdfIn PDF document text
    • http://www.darvidproperty.com/news/file/68500884338.pdfIn PDF document text
    • http://art-ball.net/files/file/marifanumuxezivawe.pdfIn PDF document text
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/16138cd70b01ec---58778010354.pdfIn PDF document text
    • http://vyveva.eu/UserFiles/File/jupedizirulutuko.pdfIn PDF document text
    • http://mayjack.com/upload/files/47306303154.pdfIn PDF document text
    • http://bakefruit.com/uploads/files/202109210112288667.pdfIn PDF document text
    • https://rafaela-motores.com/userfiles/file/56519237864.pdfIn PDF document text
    • https://arnetbilgisayar.com/upload/ckfinder/files/45782395895.pdfIn PDF document text
    • https://bibliotheque-des-arts.com/ckfinder/userfiles/files/86256829157.pdfIn PDF document text
    • https://isosklo.cz/uploads/pewubumilavikasufuz.pdfIn PDF document text
    • https://cleartunemonitors.com/ckfinder/userfiles/files/51926198857.pdfIn PDF document text
    • http://prime-standard.com/piceditor/file/diporofozeku.pdfIn PDF document text
    • http://aviatechinform.ru/sadm_files/20444002193.pdfIn PDF document text
    • http://azbuka-d.ru/ckfinder/userfiles/files/13197067647.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_off0000d763.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD763 10908 bytes
SHA-256: 2dd897224df34366ad956e6696debf2aabfd4cb3c6272e0f9a88d0cdf7ba83a9
font_01_sfnt_off0000f04e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF04E 18832 bytes
SHA-256: bfe6023e5a43b3cdd55ef1e10f22fe19238021cf71f95a892502a9cf35a4b806
font_02_sfnt_off0001208b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1208B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1