Malicious PDF — malware analysis report

Static analysis result for SHA-256 1039291d2ea134f4…

MALICIOUS

PDF

69.3 KB Created: 2021-10-02 13:33:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: adeb769bc751d79f20e8bb46c50d6bf7 SHA-1: 83bac94eefbb491f19f583843846614b72e47fb1 SHA-256: 1039291d2ea134f4c34083323ea6a388e18532fae11e1605659e71d736fb52be
166 Risk Score

Malware Insights

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

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The 'SE_BROWSER_INSTALL_LURE' heuristic strongly suggests a social engineering tactic to prompt the user to install malicious software or extensions. The numerous embedded URLs, including one pointing to 'nomylo.ru', likely serve as download or redirection points for further stages of the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

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
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://nomylo.ru/uplcv?utm_term=chester+macduffee+diving+suit PDF link annotation
    • http://www.americaninvest.net/upls/files/foseguxuxepadevaxuf.pdfIn PDF document text
    • http://tienphat.vn/imagesflashupload/file/vexesokesanerarez.pdfIn PDF document text
    • https://phu-komplex.pl/pliki/file/kewutoni.pdfIn PDF document text
    • http://epmresearch.org/userfiles/files/53697110955.pdfIn PDF document text
    • http://mpu-beratung-brendle.de/userfiles/file/woluziranejanedodax.pdfIn PDF document text
    • http://ensky-chemical.com/upload/files/vadedoxug.pdfIn PDF document text
    • https://mayphotocopydogia.com/upload/files/xepazorifi.pdfIn PDF document text
    • http://progettarecasa.com/userfiles/files/xipojafasugalenexufegex.pdfIn PDF document text
    • http://voyagevietnamlaos.com/hinhanh/file/modemejinibinemesawunese.pdfIn PDF document text
    • http://steelfurniturecn.com/d/files/tikomakokubofupejo.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/8556f637d60d8a48355e757c3c8a9cb1/38199080386.pdfIn PDF document text
    • http://lsphc.com/userfiles/file///47746390844.pdfIn PDF document text
    • http://motolargo.pl/userfiles/file/12213600359.pdfIn PDF document text
    • https://samsungdvmklima.com/upload/ckfinder/files/kefejumetenezagimuse.pdfIn PDF document text
    • https://cupanghitam.com/contents/files/80023510772.pdfIn PDF document text
    • http://kayamedbursa.com/userfiles/file/pezatuka.pdfIn PDF document text
    • http://edilcfcostruzioni.com/userfiles/files/xejawogarivifipigesebup.pdfIn PDF document text
    • https://www.notusweb.com.br/ckeditor/ckfinder/userfiles/files/92809353772.pdfIn PDF document text
    • http://www.espaciocultivarte.com/ckfinder/userfiles/files/17164237627.pdfIn PDF document text
    • https://driftwoodcc.com/userfiles/files/setopuxopujuzixupif.pdfIn PDF document text
    • https://glearningsolutions.com/userfiles/files/zubetejeviju.pdfIn PDF document text
    • http://eptesteplelek.com/uploads/file/devixabukezoxad.pdfIn PDF document text
    • https://partnermind.cz/images/files/niraxurotunele.pdfIn PDF document text
    • http://fjsxsx558.com/upload/files/90109768679.pdfIn PDF document text
    • https://netpage.info/userfiles/file/48068366903.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_off0000af30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF30 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c747.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC747 10956 bytes
SHA-256: fe95c676151579c7b777e81540a39db6670326112f551104f31d0d49a051fc08
font_02_sfnt_off0000e05f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE05F 15140 bytes
SHA-256: 778838cfbd4c8854c5df80defd5e4052b2d43e799e5d4ced1e38148ca2553561