Malicious PDF — malware analysis report

Static analysis result for SHA-256 18038a8e3742d507…

MALICIOUS

PDF

79.6 KB Created: 2021-09-18 06:58:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 2653f916358668f748e90722379d8dae SHA-1: cca67f26ea83d04d15b5aa4ab82ac2953c5dfdce SHA-256: 18038a8e3742d507b1efb1399219db9c3d43b3b0397cc776b399b5a5fd51bef7
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a high number of external URIs, many of which point to disposable hosting. The 'SE_PASSWORD_ARCHIVE_LURE' heuristic indicates the document likely instructs the user to open a password-protected archive, a common tactic to bypass gateway security. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to deliver a second-stage payload via the linked URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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://pistant.ru/uplcv?utm_term=henry+james+the+turn+of+the+screw+pdf PDF link annotation
    • http://warwick-ems.org/userfiles/file/34298691984.pdfIn PDF document text
    • http://alburigiott.it/userfiles/files/30352953954.pdfIn PDF document text
    • http://vertex-decor.com/userfiles/file/sivunuve.pdfIn PDF document text
    • http://latiendasegura.com/contable_prueba/userfiles/file/nowowikagumatevelugojotav.pdfIn PDF document text
    • http://szkolaprzybranowo.pl/ckfinder/userfiles/files/zotadijifo.pdfIn PDF document text
    • http://xedaphcm.com/luutru/files/50207758093.pdfIn PDF document text
    • https://catbasailing.com/upload/fck/file/55515197756.pdfIn PDF document text
    • http://xetaihyundai.net/upload/files/51394663919.pdfIn PDF document text
    • http://mg001.cn/upload_fck/file/2021-9-7/20210907020438629752.pdfIn PDF document text
    • http://www.jfac.kr/ckfinder/userfiles/files/nutetirazanupewaxebata.pdfIn PDF document text
    • https://arvikabc.com/images/uploadedimages/file/takunuti.pdfIn PDF document text
    • http://debeleven.net/UserFiles/File/89249389575.pdfIn PDF document text
    • https://primeodontorj.com/wp-content/plugins/super-forms/uploads/php/files/54e6f397aef55bb68552531b02916b45/zumexatakekibebawuso.pdfIn PDF document text
    • http://www.lavalledesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130517d83009---27084875853.pdfIn PDF document text
    • https://iqmuseum.mn/uploads/files/41495634792.pdfIn PDF document text
    • http://uptownherndon.com/uploads/files/64331407086.pdfIn PDF document text
    • https://hattshopping.com/admin/assets/images/ckfiles/66759291481.pdfIn PDF document text
    • http://nocleginaplus.pl/uploads/userfiles/files/96803564937.pdfIn PDF document text
    • http://epoch-making.jp/js/upload/files/dimujul.pdfIn PDF document text
    • http://ytbozhuo.com/upload/file/140059211800.pdfIn PDF document text
    • http://exhibitionchannel.com/upload/gejozelaru.pdfIn PDF document text
    • http://perfectionistpaintingnj.com/ckfinder/userfiles/files/jaruwozedisobebibaxesav.pdfIn PDF document text
    • https://odlingfamily.com/userfiles/file/likezubonaburudiwuvamulem.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_off0000cb58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB58 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e36a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE36A 19632 bytes
SHA-256: 5e56231b6d92fe381ffa4ba8bef75cc40523c43ba33bd7236f2774125242ea0d
font_02_sfnt_off000116e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116E8 11168 bytes
SHA-256: 9262fdf44bbfdbdda27ee259f7dfec3a608d6f9551c9cb8c626330ca32b86148