Malicious PDF — malware analysis report

Static analysis result for SHA-256 405b8f79fc8cbf22…

MALICIOUS

PDF

93.9 KB Created: 2021-09-14 06:46:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: f8f74f5262a510d57ca32140e7075e5a SHA-1: c5144b8b286f49421b501a36a0d5fe268c30efde SHA-256: 405b8f79fc8cbf223455dab6caf995dc7ab074034a814bb881651a91fe79eb6e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs pointing to a link farm hosted on disposable domains, indicating a phishing or malware distribution attempt. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, noting a high number of distinct hosts and links. No scripts were extracted, but the structure suggests it's designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 http://studioriboldi.eu/userfiles/files/mipediwuriwuzaxomukusek.pdf In PDF document text
    • https://agronlogistics.com/userfiles/files/zilajigikujuni.pdfIn PDF document text
    • https://shindah.com/images/ckeditor_img/files/zawamov.pdfIn PDF document text
    • http://hoilhpnqbthanh.com/upload/file/vubejira.pdfIn PDF document text
    • http://secureyun.cn/uploadfile/file///2021091213590936.pdfIn PDF document text
    • https://nnkcreations.com/userfiles/file/20952837117.pdfIn PDF document text
    • http://15881588.com/ckupload/files/tajotarifogepasagazigukas.pdfIn PDF document text
    • https://kocarbon.vn/luutru/files/nebabenok.pdfIn PDF document text
    • http://unityproductions.com/upload/files/titojomaxidajakugatekaje.pdfIn PDF document text
    • http://precisionsurgicalworks.com/alpha/ckfinder/userfiles/files/70895851469.pdfIn PDF document text
    • https://www.tahitotfalu.hu/ckfinder/userfiles/files/gakiwoli.pdfIn PDF document text
    • http://zopos.zohukum.com/ckfinder/userfiles/files/38397780645.pdfIn PDF document text
    • http://voijin.com/userfiles/files/mofij.pdfIn PDF document text
    • http://sake2metustin.com/uploads/files/54908471576.pdfIn PDF document text
    • https://lbk-ingatlan.hu/uploads/file/28758334964.pdfIn PDF document text
    • http://zapatosperezcabrera.com/ckfinder/userfiles/files/89756574551.pdfIn PDF document text
    • http://canxetaidientu.com/images/file/68547652387.pdfIn PDF document text
    • http://vngo-cc.vn/cooker/public/files/raweloxelelojewa.pdfIn PDF document text
    • http://kiko168.com/UploadFile/file/20210904092338774.pdfIn PDF document text
    • http://nkmate.com/FileData/ckfinder/files/20210913_5D81E847C2A5816C.pdfIn PDF document text
    • http://portamarioarchitetto.eu/userfiles/files/94487792101.pdfIn PDF document text
    • https://rajaketiga.com/contents/files/98666020160.pdfIn PDF document text
    • https://yennenga.org/business_school/uploads/file/52413055076.pdfIn PDF document text
    • http://aatmicscience.org/asuserfiles/file/nomilofo.pdfIn PDF document text
    • https://thieumaunao.vn/workspace/develop/uploads/ck_upload/files/64126530249.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=men%27s+day+2019PDF 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_off00010d6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D6F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012581.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12581 17408 bytes
SHA-256: eb3f753bf269804e236439cd14bab732d90fc79e6fa53dfa422b36047afea7e8
font_02_sfnt_off00015241.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15241 10388 bytes
SHA-256: 9cb8c0350d57645c5064eb13ef35507986e8a8308385bc08c6c32fb1d445fbd8