Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4535c814b1fb69d…

MALICIOUS

PDF

70.6 KB Created: 2021-09-25 12:14:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 9d76698297b1ade56452cc25065eefb0 SHA-1: 372143f3a42f3bfd299a4f1282c441b672387e59 SHA-256: a4535c814b1fb69d2e161a8371433ebf5d96797f8558eff1a8336450b7cac750
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged as malicious by a machine learning classifier and ClamAV, indicating a high likelihood of malicious intent. The presence of embedded JavaScript and a large number of external links, many pointing to disposable domains, suggests this document is designed to lure users to potentially harmful websites. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a link farm strategy.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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 http://manilag.com/FileData/ckfinder/files/20210905_9F2A7DEE4C1850F8.pdf In PDF document text
    • http://www.ondebiz.com/userfiles/file/9103980556.pdfIn PDF document text
    • http://alfonsoguiggiarchitetto.it/userfiles/files/vekapasukovazido.pdfIn PDF document text
    • https://nedimgame.com/calisma2/files/uploads/mafuxulutaxororolobi.pdfIn PDF document text
    • http://praxis-greve-polley.de/web/editor/files/fewogafi.pdfIn PDF document text
    • http://mg001.cn/upload_fck/file/2021-9-1/20210901102649181107.pdfIn PDF document text
    • https://hsse.hssanesteban.cl/files/63044543632.pdfIn PDF document text
    • https://history.tlshaa.org.tw/ckfinder/userfiles/files/91947311244.pdfIn PDF document text
    • http://tumwebthailand.com/ckfinder/userfiles/files/zoxiwarujatifew.pdfIn PDF document text
    • http://www.offshoreyachts.net/web_upload/editor/files/baxokin.pdfIn PDF document text
    • http://conservativista.com/js/ckfinder/userfiles/files/dafese.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/o9v0cfsccqj1j999aon25olre6/97889532977.pdfIn PDF document text
    • https://catherinehourihan.art/wp-content/plugins/super-forms/uploads/php/files/d8f2eccdcb5f1376d96f6077e7a5d2f0/85942987620.pdfIn PDF document text
    • https://ntiverification.com/userfiles/file/dujetimeruxavukowomatonem.pdfIn PDF document text
    • http://xiangzhuan.tw/upload/files/97092019374.pdfIn PDF document text
    • http://haenuri.net/ckupload/files/kamepobag.pdfIn PDF document text
    • http://bikipvuikhoedep.com/app/webroot/files/editor_upload/files/53104364975.pdfIn PDF document text
    • https://www.eos.org.eg/ckfinder/userfiles/files/wigevujedinig.pdfIn PDF document text
    • http://lunaleo.pl/userfiles/file/lexide.pdfIn PDF document text
    • http://www.pattyn360.com/upload/forum/files/12729895996.pdfIn PDF document text
    • http://itps-group.com/uploadfiles/file/wenivorikikuvepa.pdfIn PDF document text
    • http://xn--3bsx3iw22bmot.com/filespath/files/20210904124447.pdfIn PDF document text
    • http://yoshitomo-kokubunji.com/jcfiles/file/98431547876.pdfIn PDF document text
    • http://cinstech-inspect-survey.com/fckeditor_userfiles/file/33713650598.pdfIn PDF document text
    • http://akpanlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/18883577754.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=racing+games+free+download+for+windows+7PDF 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_off0000b1de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1DE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c9f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9F5 10904 bytes
SHA-256: de52388d5f381e633e64210ba214816a574535f210a34472149546625764e77f
font_02_sfnt_off0000e30f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE30F 16348 bytes
SHA-256: 1084e97b89008a8fe11c6232de239560821834ff742d7c3bc5add87bc9e27a5b