Malicious PDF — malware analysis report

Static analysis result for SHA-256 a57316ab1310d16b…

MALICIOUS

PDF

82.7 KB Created: 2021-09-12 11:28:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 850367d02764a99a6ff1d1cbd9ae61b3 SHA-1: bac0f6e102c7b7ab764f839107f59fd92ed4469b SHA-256: a57316ab1310d16b6a3cceeb324877ffcd658980a9cb8bd6a61da29ce09e4f0d
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains embedded JavaScript and external URIs, with a high ML classifier score and ClamAV detection indicating malicious intent. The 'Clipboard command execution lure' heuristic strongly suggests the document instructs users to copy/paste commands into a shell, a common technique for downloading and executing secondary payloads. The presence of external URLs, including one identified as a link farm, further supports a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Clipboard command execution lure high SE_CLIPBOARD_COMMAND_LURE
    Document tells the user to copy or paste clipboard content into Run, PowerShell, cmd, or another shell-like execution context
  • 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 http://ekhoron21.mn/uploads/files/zetisimewepipekufubi.pdf In PDF document text
    • http://nanopena.cz/upload/file/wumisigeleroxelexefefogiz.pdfIn PDF document text
    • http://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613192fd81545---goduvarapenesupagiviwer.pdfIn PDF document text
    • http://autosoftware.company/autoresponders_images/files/wenawexedige.pdfIn PDF document text
    • http://basaritarim.net/admin/editor_resim/file/zalidubax.pdfIn PDF document text
    • http://motivationandmomentum.net/ci/userfiles/files/68725262822.pdfIn PDF document text
    • http://ks4073.com/file_media/file_image/file/wekuwafadoba.pdfIn PDF document text
    • http://xinyuemu.net/assets/202109/files/20210901065124951685.pdfIn PDF document text
    • http://movediary.com/userfiles/file/rusomanedevowuj.pdfIn PDF document text
    • http://artetendasud.it/userfiles/files/pavotejosew.pdfIn PDF document text
    • http://myphamso1.net/uploads/files/91970905896.pdfIn PDF document text
    • https://tanthueviet.vn/img_data/files/vibajazarenikopufifumulu.pdfIn PDF document text
    • https://landbar.com/app/webroot/js/ckfinder/core/connector/upload/files/zobifatogevasifubanadak.pdfIn PDF document text
    • http://sporteambiente.it/ckfinder/userfiles/files/pitabadalekamaruzuxakos.pdfIn PDF document text
    • http://szcftz.com/upload/vovalakefodumotupasuse.pdfIn PDF document text
    • http://perila-vrn.ru/userfiles/file/rovidemipoge.pdfIn PDF document text
    • http://borik.customreal.sk/data/files/81854555104.pdfIn PDF document text
    • https://maftplayer.net/calisma2/files/uploads/vefixa.pdfIn PDF document text
    • http://0985028898.kad.tw/kads/ckfinder/userfiles/files/40856848469.pdfIn PDF document text
    • http://poslovniimenik.net/firme_data/files/24866482590.pdfIn PDF document text
    • https://primer-spb.ru/files/files/90262933463.pdfIn PDF document text
    • http://copy-office.it/userfiles/file/96528402070.pdfIn PDF document text
    • http://psycare-spb.com/userfiles/file/fidonijetofisonas.pdfIn PDF document text
    • http://www.fred-robin.com/ckfinder/userfiles/files/60991506820.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=how+to+sync+bookmarks+in+chrome+androidPDF link annotation
    • 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_off0000daa9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAA9 18912 bytes
SHA-256: 67e0aa99e9a1de8b4139c0ac196899a5b98fce48b092fa16fb2760d92f439291
font_01_sfnt_off00010b78.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B78 11012 bytes
SHA-256: 391c2de53484a55a0d621aa54389de5546aeeb46484adfb462aa93bb04b572a4
font_02_sfnt_off000124f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124F5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1