Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8873101abfaa1c0…

MALICIOUS

PDF

72.2 KB Created: 2021-09-30 12:52:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 267bb56a4ae352f5b718cc2818cbbfe7 SHA-1: ed0b4da561fb9c66c4013068029b675e5b0de8e3 SHA-256: a8873101abfaa1c0dcaac0f7dfe1fe3395a2c39472e1c1e4d7c1c929dacd3992
164 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a link farm pointing to various domains, some of which are identified as compromised CMS uploads. The primary purpose appears to be directing users to download applications or visit malicious sites, as indicated by the 'utm_term=shareit+download+app+free' parameter in one of the URLs. The ML classifier and ClamAV detection strongly suggest malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9915

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
  • 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://indianspringhomes.com/userfiles/files/2848169750.pdf In PDF document text
    • https://zmiz.hr/userfiles/file/piguled.pdfIn PDF document text
    • https://maxflowfans.com/userfiles/file/28785585836.pdfIn PDF document text
    • http://bhk-aindling.com/userfiles/files/dajib.pdfIn PDF document text
    • http://z500.si/files/lowifiweredogefaxiruk.pdfIn PDF document text
    • http://eco-versute.com/app/webroot/ckfinder/userfiles/files/76249444872.pdfIn PDF document text
    • http://richmore.kr/uploadfile/fckeditor/file/denedemogominafaxave.pdfIn PDF document text
    • http://heizler.hu/files/file/dodeviwazokewekom.pdfIn PDF document text
    • https://www.simcoerecovery.net/wp-content/plugins/super-forms/uploads/php/files/mdo8fhap6l51tcv38ss3d484hp/8017089910.pdfIn PDF document text
    • https://rlmahtani.com/userfiles/files/xonara.pdfIn PDF document text
    • http://a-xian-coat.com/uploads/files/202109232200291578.pdfIn PDF document text
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614a44a48f08f---57333629450.pdfIn PDF document text
    • https://mehreganimaging.com/images/upload/files/naxomugo.pdfIn PDF document text
    • http://ping-property.com/user_img/files/40119487595.pdfIn PDF document text
    • http://kaus21.com/userData/board/file/golutudimu.pdfIn PDF document text
    • http://blekinge.boj.se/uploads/userfiles/files/6184114259.pdfIn PDF document text
    • http://stilistspb.online/public/files/uploads/files/mixefanolewan.pdfIn PDF document text
    • https://linlinline.biz/js/ckfinder/userfiles/files/21492242152.pdfIn PDF document text
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1614141f112e1e---88634541620.pdfIn PDF document text
    • https://xn--fiqa735be48e.com/upload/files/62722177919.pdfIn PDF document text
    • http://iranjobex.com/cache/fck_files/file/90706355191.pdfIn PDF document text
    • https://alakharia.com/public_html/userfiles/file/xikozizizuz.pdfIn PDF document text
    • http://pnktools-th.org/ckfinder/userfiles/files/lupek.pdfIn PDF document text
    • https://igraonica.me/userfiles/file/linodo.pdfIn PDF document text
    • http://smsgurugram.com/miet/assets/files/88312014094.pdfIn PDF document text
    • http://halmar.info/userfiles/file/sudovid.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=shareit+download+app+freePDF 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_off0000b6b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB6B8 10588 bytes
SHA-256: 4c2338dbabda489d1aeed368754a58fccedfe1b82f34718b8dc5bf0a6124eb33
font_01_sfnt_off0000cee3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEE3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e6f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6F5 17224 bytes
SHA-256: d251ce765456742e468496002d9b52995c1be975d7bcd67386f5e8409b911cb8