Malicious PDF — malware analysis report

Static analysis result for SHA-256 8ca9c66e99ff168f…

MALICIOUS

PDF

85.5 KB Created: 2021-09-18 18:12:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 19f9eee414f7a287861d59726b93e25c SHA-1: 5b8bff211ad308b2603742ee343512d3af137b2e SHA-256: 8ca9c66e99ff168f5e8150d976b50ffcbb799d4589225ba0433855f3493ea7f7
164 Risk Score

Malware Insights

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

The sample is a PDF file containing embedded JavaScript, which is a common technique for exploiting vulnerabilities and delivering malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The presence of numerous links to potentially compromised or disposable hosting sites further supports this assessment, suggesting an attempt to lure users into downloading further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://soft-pro.hr/upload/datoteke/11583306153.pdf In PDF document text
    • http://3sdent.com/upload/files/xejomuditofonero.pdfIn PDF document text
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/a985a8bb7efdcd172cdf80b46b4b95b8/60970904198.pdfIn PDF document text
    • http://pmrs.ps/userfiles/file/laxipim.pdfIn PDF document text
    • http://topmebli.com/content/xuploadimages/file/74462480284.pdfIn PDF document text
    • http://bjbtrh.com/files/pic/file/70158399452.pdfIn PDF document text
    • https://corumosmanlimakina.com/js/ckfinder/userfiles/files/65507962201.pdfIn PDF document text
    • http://cdenito.net/userfiles/file/wadozesopamigividul.pdfIn PDF document text
    • http://shimamura-mail-order.com/userfiles/file/dixuvefetanodimubov.pdfIn PDF document text
    • http://gadkowski.pl/repository/filemanager/file/70218588819.pdfIn PDF document text
    • http://toflight.mobi/attachment/ckeditor/files/2aa3886a727b166a27c59bc616217df1.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/161419cfe05215---xiwexogexo.pdfIn PDF document text
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/161336f56e8d35---xojilurasaxonosuxew.pdfIn PDF document text
    • http://tpdw.pl/userfiles/file/70064630705.pdfIn PDF document text
    • https://isagrinio.gr/userfiles/fajakux.pdfIn PDF document text
    • http://summitremodelinginc.com/userfiles/files/kadetajakon.pdfIn PDF document text
    • http://ipceurope.be/assets/file/kapemak.pdfIn PDF document text
    • http://thechitay.com/uploads/userfiles/file/72908794116.pdfIn PDF document text
    • http://tanriovermensucat.com/uploads/genel/files/vupuratapuzubagikogum.pdfIn PDF document text
    • http://drironcat.com/images/file/93173015889.pdfIn PDF document text
    • http://live-lessons.net/lcj/web/uploads/assets/file/44016108711.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=angel+has+fallen+free+online+moviePDF 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_off0000e690.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE690 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fea7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEA7 10612 bytes
SHA-256: 18842745095a0b72036b2d2dc0891b64beba56eeb7ee8fe1b168d2c9cd9f8a40
font_02_sfnt_off000116ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116BA 19004 bytes
SHA-256: fcf4b525f36e3f8c32eddbc2f8e6bd2810fd92aaa4fd0a45debd9ede1dfa99a8