Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b255cd0cb6a9612…

MALICIOUS

PDF

68.9 KB Created: 2021-09-27 11:02:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 91d2a22a5bb7287ed874870755f45d9d SHA-1: 19c096640b822e623066aedda12f22689e47e495 SHA-256: 5b255cd0cb6a9612747d4430d4d82f66584960ecbe1ff465ceb020addea6a21e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a machine learning classifier and ClamAV, indicating malicious intent. The presence of numerous external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic suggest the document is designed to redirect users to potentially harmful websites. No scripts were extracted, but the structure and URL patterns are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • 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.
  • 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://el-tall.pl/pics/file/94178825468.pdf In PDF document text
    • https://at1apigroup3.com/contents/files/96888572537.pdfIn PDF document text
    • https://shturnev.com/files/foFKED/file/15820676152.pdfIn PDF document text
    • http://visit-pune.com/userfiles/file/20549817668.pdfIn PDF document text
    • https://cornwallstaffagency.com/userfiles/file/vemimupiwuzepufukibi.pdfIn PDF document text
    • http://xn--82cac8d3ajrc0gd0bo4a7nf3qg.com/userfiles/files/50558608682.pdfIn PDF document text
    • http://dsagco.com/Upload/file/14243281069.pdfIn PDF document text
    • https://noelex22.org/userfiles/file/91473506446.pdfIn PDF document text
    • https://saksisan.com/upload/ckfinder/files/lemifi.pdfIn PDF document text
    • http://cafemsoffice.com/userfiles/files/63134176755.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e6722923e6---8291867321.pdfIn PDF document text
    • http://vdadanang.vn/app/webroot/assets/files/48475619424.pdfIn PDF document text
    • http://xn--80aaa1acmiejxr6d7fg.xn--p1ai/data/files/xuvilexafimuluxilibulawup.pdfIn PDF document text
    • http://roomyab.ir/basefile/roomyabir/files/migoginezulifobajo.pdfIn PDF document text
    • http://wcsps.com.tw/ckfinder/userfiles/files/tebixolaleledadibuk.pdfIn PDF document text
    • http://machinesupplier.cn/data/product/file/2021917_173939_862.pdfIn PDF document text
    • http://hamishehbaharcarpet.com/My_Project/Hamishe_bahar/ahar_img/files/vuwakidosugevolu.pdfIn PDF document text
    • http://deeringbayrealestate.com/userfiles/files/pujevunanosijifuv.pdfIn PDF document text
    • http://powercleanperu.com/cms_powerclean_2015/sgi_userfiles/userfiles/files/pulosawaxamasitofeba.pdfIn PDF document text
    • http://zgic.ru/!upload/files/28455350749.pdfIn PDF document text
    • http://pk.mo/userfiles/file/25780041333.pdfIn PDF document text
    • http://forma8.kz/ckfinder/userfiles/files/1899496224.pdfIn PDF document text
    • http://lycee-elm.org/userfiles/file/tutiwabobozovo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=app+cinema+hd+v2PDF 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_off0000ae34.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE34 15952 bytes
SHA-256: a84f3c4b7a4b5bb372b10e748aa8fbfb9cb32ed9e43135755d5242a60b71c43a
font_01_sfnt_off0000d6ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6CE 10416 bytes
SHA-256: 5299b80f9ff0398e0e0d4f1074edf08ecfe9abb7df30d0caea699847f98fcebc
font_02_sfnt_off0000ee3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE3E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1