Malicious PDF — malware analysis report

Static analysis result for SHA-256 e77167fc31011f54…

MALICIOUS

PDF

75.7 KB Created: 2021-09-08 21:10:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 997723fdcfaf459c5385c1f6f530deed SHA-1: 1d59cf97803ad9a566c533e035ab6d1a5a6d46c4 SHA-256: e77167fc31011f544a27ca61f3fc17e2f2dcb5762e2bfaff57798ae4de431ce3
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier, with heuristics indicating embedded JavaScript and a link farm structure. The presence of numerous external URIs, including one pointing to 'infrive.ru' with a 'pdf converter' UTM term, suggests a phishing or malware distribution lure. The embedded JavaScript likely facilitates the redirection or download of a secondary payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://infrive.ru/uplcv?utm_term=online+pdf+converter+in+word+document PDF link annotation
    • https://kolegium.inaheart.org/upload/files/mepuruxoxemikipusu.pdfIn PDF document text
    • http://iwort.de/userfiles/file/94657251168.pdfIn PDF document text
    • http://nenayu.com/filespath/files/20210903064816.pdfIn PDF document text
    • http://ibrahimalsada.com/pics/file/tuzuwetisinipovir.pdfIn PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612efe9112f44---91086749430.pdfIn PDF document text
    • https://alpinashop.bg/files/woreweso.pdfIn PDF document text
    • http://goodfortune.hk/UpLoadFile/file///vipun.pdfIn PDF document text
    • http://kasand.com/userfiles/mulovumurojejarabo.pdfIn PDF document text
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612eaca682800---lawiwenutujizibug.pdfIn PDF document text
    • https://currenwatch.myhost360.cn/file/upload/files/09-07-18-46-17-36.pdfIn PDF document text
    • http://lafenicealcamo.it/userfiles/files/varog.pdfIn PDF document text
    • http://www.artefuoricentro.it/js/lib/ckfinder/userfiles/files/88772683969.pdfIn PDF document text
    • http://xn--66-6kc8bfmkmjd.xn--p1ai/admin/ckfinder/userfiles/files/1322439340.pdfIn PDF document text
    • https://eastmanllc.net/ckfinder/userfiles/files/warelazu.pdfIn PDF document text
    • http://www.guus.edu.mn/ckfinder/userfiles/files/gudevuw.pdfIn PDF document text
    • http://seghers.kr/data/editor/file/21204958976133bba6b50a0.pdfIn PDF document text
    • http://www.sec-ollivier-associes.fr/www/upload/file/zimagorewexototakorako.pdfIn PDF document text
    • http://pscworld.eu/ckfinder/userfiles/files/36827429877.pdfIn PDF document text
    • https://tele-video.ru/upload/files/lesogifutu.pdfIn PDF document text
    • http://sithome.com/upfiles/file/20210903010539.pdfIn PDF document text
    • https://alyosserspneed.com/userfiles/files/26015038601.pdfIn PDF document text
    • http://secohthailand.com/file_media/file_image/file/53655488922.pdfIn PDF document text
    • http://svarovani-tig.cz/userfiles/file/61253328032.pdfIn PDF document text
    • https://bluza-shop.ru/content/File/jelasobujezujenekugobil.pdfIn PDF document text
    • http://tucsokszekszard.hu/images/news/file/76651492639.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_off0000c3e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3E0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dbf7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBF7 10728 bytes
SHA-256: 62872b258624d49b5f971031958f90d05d67bf756df6d41391e67764930e398e
font_02_sfnt_off0000f4a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4A0 16936 bytes
SHA-256: 87071faaa859807e4f0a28753b8559d9e1834d3d40042d4110d142e5f93048be