Malicious PDF — malware analysis report

Static analysis result for SHA-256 9f23a9f4539c9ac9…

MALICIOUS

PDF

80.4 KB Created: 2021-09-18 13:05:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7f46b62f3509592d27369b347bfcabc5 SHA-1: b34d9623179c62d540083422e341ffd95c5a8925 SHA-256: 9f23a9f4539c9ac9ddfd3b5d6ca339c4fbe7db88f15e132321eff5438b0b0a35
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. Heuristics indicate it functions as a link farm, with many external URIs pointing to various domains, including compromised WordPress upload storage. The document body is heavily obfuscated and unreadable, suggesting it is not intended for direct user interaction but rather to host malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 6

  • 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.
  • 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://cructi.ru/uplcv?utm_term=decompile+unity+apk
    • http://kronospan-mofa.hu/editor_up/vofurikezakurejebamut.pdf
    • http://waetsukai.jp/system/ckfinder/userfiles/files/mulazajobulux.pdf
    • http://aotwresort.org/ckfinder/userfiles/files/dizatunuvegamepen.pdf
    • http://portalpr-b2b.es/img/user//file/_0716099001630529371.pdf
    • http://furnitura-syndicat.ru/ckeditor/ckfinder/core/connector/php/uploads/files/noxuxoxetaduvujik.pdf
    • https://jecoexports.com/ckfinder/userfiles/files/49120834696.pdf
    • http://host.keraladreamhomes.com/~viswabrahmathach/admin/fckeditor/editor/filemanager/connectors/php/userfiles/file/milomojariwejiku.pdf
    • http://ncdesign.it/userfiles/files/keloluwalaziwasupi.pdf
    • http://ambvetesopo.eu/userfiles/files/47218734561.pdf
    • https://growmytruck.com/wp-content/plugins/super-forms/uploads/php/files/e066256f45f8a6fcdec32b8a3beb6844/fodelakogibuxunafimuse.pdf
    • https://www.kiakaha.gr/wp-content/plugins/super-forms/uploads/php/files/sk7h71euvnebd8bjc88rin71na/3623325331.pdf
    • http://chiaranannini.com/userfiles/files/76709448976.pdf
    • https://tsydesign.com/userfiles/jws/files/bebulu.pdf
    • http://legalinet.eu/userfiles/files/92008951837.pdf
    • http://dlshixiang.com.cn/ckfinder/userfiles/files/sajawodajaxevixapapokume.pdf
    • https://shibbirs.com/media/files/48657529827.pdf
    • http://ranahytta.com/ckfinder/userfiles/files/didalopezotevu.pdf
    • http://yibetter.com/data/files/tepebobebufon.pdf
    • https://fokusmedia.com/images/uploads/12330284488.pdf
    • http://baocaosuhoatoc.com/luutru/files/6193221279.pdf
    • http://acetuitioncentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16140bd6ab0793---giminuk.pdf
    • https://catherinehourihan.art/wp-content/plugins/super-forms/uploads/php/files/cd523e7ab7e9c24f32d5bac00e12a2d8/bewibawasedonisumekona.pdf
    • http://linpus.com/app/webroot/userfiles/files/58498151943.pdf
    • http://csc0851.com/userfiles/file/20210918072944_g0l0v7.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d4b6.bin
a7bfb7e4a89d9d6bbb642532e1d0ee919bd088ad35324fc0ff237ecbaae4b67c
pdf-font-stream PDF embedded font (sfnt) at offset 0xD4B6 10576 bytes
font_01_sfnt_off0000ecd9.bin
cf4a2b356802ed092d5c1c409fce807a709f6760ef818e521e09087b63861def
pdf-font-stream PDF embedded font (sfnt) at offset 0xECD9 18232 bytes
font_02_sfnt_off00011c62.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11C62 16792 bytes