Malicious PDF — malware analysis report

Static analysis result for SHA-256 21b41aa25454bb26…

MALICIOUS

PDF

85.1 KB Created: 2021-09-21 15:46:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 74ffcebf9fb5842ddbcb87dda335966a SHA-1: 2cf97b33314988a764a613fa4a3dff5ed24218e0 SHA-256: 21b41aa25454bb2625e9ef3f083784be6db8dad9246f70abb8cab220a6815e22
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, with a high concentration of links pointing to disposable domains, indicative of a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and embedded links are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 5

  • 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.
  • 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://soccerauquebec.com/userfiles/file/gupagamezekax.pdf In PDF document text
    • http://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/161359edbb1d89---femidojovobidudasumuxip.pdfIn PDF document text
    • http://resortcrimea.com/ckfinder/userfiles/files/68501497515.pdfIn PDF document text
    • https://siliconautomation.com/userfiles/file/26754226256.pdfIn PDF document text
    • https://dalton-english.com/userfiles/file/13313752295.pdfIn PDF document text
    • http://tatagz.com/uploadfile/files/varolurovejoludaref.pdfIn PDF document text
    • https://sukienmiennam.com/userupload/files/dotivowixeme.pdfIn PDF document text
    • http://kevinmcallisterlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/41607522365.pdfIn PDF document text
    • http://tokyoto.pl/UserFiles/file/57870383448.pdfIn PDF document text
    • http://gachtrangtritranvinhtin.com/gachtrangtritranvinhtin/Images_upload/files/belilebidutajof.pdfIn PDF document text
    • http://www.binghan.my/userfiles/file/33214284205.pdfIn PDF document text
    • http://zelene-centrum.cz/webpagebuilder/ckfinder/userfiles/files/51240699894.pdfIn PDF document text
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134890d0bed1---2675902442.pdfIn PDF document text
    • http://htygroup.com/upload/files/34752733278.pdfIn PDF document text
    • http://yanarfabrics.com/firma/files/92669902519.pdfIn PDF document text
    • https://dakotaterritorydevelopment.com/ckfinder/userfiles/files/seradefamevisoxebuvidilub.pdfIn PDF document text
    • https://arnetbilgisayar.com/upload/ckfinder/files/miwanerijenotupak.pdfIn PDF document text
    • https://dla-pracownika.pl/pliki_user/File/jubuxijivudarakewem.pdfIn PDF document text
    • https://deltarents.com/upload/ckfinder/files/60788444025.pdfIn PDF document text
    • https://thuanxuongmonmb.com/admin/webroot/upload/image/files/74684858812.pdfIn PDF document text
    • http://wyadonline.com/userfiles/file/vadowejisokaza.pdfIn PDF document text
    • https://comtraining.cl/userfiles/files/59627863596.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=best+fonts+for+android+phonesPDF 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_off0000e85a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE85A 17620 bytes
SHA-256: 6075bff22101fb74a1966b7fddce4694d7afda127ea6dc5e35651d8daa000e80
font_01_sfnt_off00011680.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11680 10600 bytes
SHA-256: 42c44a82a076272c92c80f866235609d3472157c4348debe83030934331470c6
font_02_sfnt_off00012eb0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12EB0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1