Malicious PDF — malware analysis report

Static analysis result for SHA-256 181c03a5a81c92be…

MALICIOUS

PDF

84.5 KB Created: 2021-09-17 07:34:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: ee548c7537497a4ebf1348358ed86f3f SHA-1: a445d53a1027917d9ba90a6aa052593b05fc4bee SHA-256: 181c03a5a81c92be44f399e167ca0f03e41478985cdd96333dd36eb9594b96b4
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains numerous embedded URLs, many of which point to disposable domains and are structured as link farms. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a deliberate attempt to create a large number of links on low-reputation hosting, likely to obscure malicious activity or distribute further payloads. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://philabc.ru/uplcv?utm_term=kindergarten+2+download+apk PDF link annotation
    • https://kimansion.com/uploads/file/99637556438.pdfIn PDF document text
    • http://brmxn.com/userfiles/file/20210909060052_yzwtz1.pdfIn PDF document text
    • https://vandolderskb.com/images/usr/lebefagibapexal.pdfIn PDF document text
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/161305f2466ba4---412616869.pdfIn PDF document text
    • http://tverzhilservis.ru/foktver.ru/ckfinder/userfiles/files/miterebexafimofuzojosekun.pdfIn PDF document text
    • http://syntrend.critical.tw/upload/files/zakidizonut.pdfIn PDF document text
    • http://rutka.pl/media/upload/files/21d72146f1dc2c220d529ba9010147ac.pdfIn PDF document text
    • http://metrocars.london/survey/userfiles/files/33533200192.pdfIn PDF document text
    • https://hospvetcentral.pt/site/upload/file/kupuxoxux.pdfIn PDF document text
    • https://festivaldelmaridaje.com/sgi_userfiles/userfiles/files/57385103262.pdfIn PDF document text
    • http://klhl.com/userfiles/file/wedutaxidi.pdfIn PDF document text
    • http://shopcode.ru/uploads/file/tapemomorikedoposanu.pdfIn PDF document text
    • https://anjingliar.com/contents/files/79065295343.pdfIn PDF document text
    • https://subded.org/userfiles/file/56530194550.pdfIn PDF document text
    • https://greenboo.vn/uploads/files/sunazuvo.pdfIn PDF document text
    • http://guitarenko.fr/img/files/60613026614.pdfIn PDF document text
    • https://kmkmekanik.com/upload/ckfinder/files/82454244126.pdfIn PDF document text
    • http://findmecakes.com/userfiles/files/19887174446.pdfIn PDF document text
    • https://europawindow.com/app/webroot/img/main_content/files/napitaxe.pdfIn PDF document text
    • https://eclearusa.com/images/file/94836077313.pdfIn PDF document text
    • http://gilendor.cz/userfiles/file/viwesuzajuvomujun.pdfIn PDF document text
    • http://quartierdete.fr/uploads/fckeditor/file/zutuxijamalajilamop.pdfIn PDF document text
    • http://designgaleria.hu/userfiles/file/tipapalivosatipopi.pdfIn PDF document text
    • https://slotsonline.ro/app/webroot/files/userfiles/files/jomobat.pdfIn PDF document text
    • http://tourbusan.net/FileData/ckfinder/files/20210914_FE4DC7808FCAF0A1.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_off0000e43a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE43A 10688 bytes
SHA-256: 7ecb07f7222a496bbce42cb557c1e8e6d1c402238901146afa825b373130c467
font_01_sfnt_off0000fcb0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCB0 18112 bytes
SHA-256: 3a9cefc3bea6597dd105920483edf10f6329c13deeb72225e82cf3a00a5f207c
font_02_sfnt_off00012bdf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BDF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1