Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8f6bbe2de5eb7aa…

MALICIOUS

PDF

74.9 KB Created: 2021-09-18 23:36:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 69f97ce056e6f62b783dfb65c34515dd SHA-1: bfbbbcd902b954345dd9f7ddd2f5cc2728230280 SHA-256: b8f6bbe2de5eb7aa048b874a96e971a9793d42d5675f1e09f94d899c362c3d9a
82 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and multiple external links, including one identified as a potential link farm on disposable hosting. The ML classifier strongly flagged this PDF as malicious, and the presence of a visual download button suggests a lure to download a secondary payload. The embedded JavaScript likely facilitates the download and execution of this payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 6

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://smidgel.ru/uplcv?utm_term=pdf+to+excel+c%23 PDF link annotation
    • http://yoshitomo-kokubunji.com/jcfiles/file/narok.pdfIn PDF document text
    • http://conservativista.com/js/ckfinder/userfiles/files/zejolivov.pdfIn PDF document text
    • http://aptwash.com/userData/ebizro_board/file/79920939477.pdfIn PDF document text
    • https://kanat.com/upload/ckfinder/files/womexada.pdfIn PDF document text
    • https://themodernla.com/wp-content/plugins/super-forms/uploads/php/files/228926c480b5e5a958f7490ea2245b4b/67421428625.pdfIn PDF document text
    • http://apart1day.ru/file/sawakuwuvobuxi.pdfIn PDF document text
    • https://nic-irq.com/userfiles/files/16746634271.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/16130e6ad27a4a---gotoferisuvudugelinuwirap.pdfIn PDF document text
    • http://ipoz.pl/userfiles/file/87562271524.pdfIn PDF document text
    • http://master-stroi76.ru/userfiles/file/jujedopojawosijokaxope.pdfIn PDF document text
    • http://aotwresort.org/ckfinder/userfiles/files/ribuferulanugopamim.pdfIn PDF document text
    • http://daisin1977.com/js/upload/files/2571758008.pdfIn PDF document text
    • http://wedding-box100.com/uploads/files/202109132146433686.pdfIn PDF document text
    • https://mut-zur-veraenderung-hambuch.de/userfiles/file/vufetofexebutedawoweva.pdfIn PDF document text
    • http://studioingegneramato.com/userfiles/files/fetevaxerokuxekevubaxomer.pdfIn PDF document text
    • http://currycornersugarland.com/admin/images/file/xobog.pdfIn PDF document text
    • http://www.temaricerca.com/entry2013/admin/ckfinder/userfiles/files/21820803002.pdfIn PDF document text
    • https://areicon.com/images/file/28099293418.pdfIn PDF document text
    • https://imad0c0.com/js/ckfinder/userfiles/files/5767748425.pdfIn PDF document text
    • https://brukspec.pl/upload/file/fikojixasezebaxadixamibo.pdfIn PDF document text
    • https://bursakaynak.com/userfiles/file/65452553977.pdfIn PDF document text
    • http://galaxyjewel.cn/uploadfile/files/jogekaloreliralox.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_off0000c565.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC565 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dd7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD7B 9944 bytes
SHA-256: f5f9b7aa05a159480c10428edc70d95070384f04eb0e8df3adbc0ea75e45215f
font_02_sfnt_off0000f39c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF39C 16484 bytes
SHA-256: 22e6af5ed8e74ea82a30af5d5c3ab88bb62bcbf1722ff99604e89b41ba8c3321