Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb55ccbdfc6f8b8c…

MALICIOUS

PDF

74.8 KB Created: 2021-04-07 08:00:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 5f74f91ac7f468128685f4789fb9c6b4 SHA-1: ef2ece0a19d1528712ae6ea5fd9de3e9e5b40900 SHA-256: cb55ccbdfc6f8b8c04e69dace6489431dd580ff50b2676b8afa8e52455ae3387
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristic firings suggest it is part of a link farm or SEO manipulation scheme, directing users to numerous external PDF files. The embedded URLs, such as 'https://kuzutuzo.ru/award?keyword=abcde+skin+cancer+pdf', are likely used to drive traffic or host malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://kuzutuzo.ru/award?keyword=abcde+skin+cancer+pdf
    • http://julasopupep.iblogger.org/63583318918.pdf
    • https://static.s123-cdn-static.com/uploads/4456393/normal_5ff9efc380232.pdf
    • https://mudituzeko.weebly.com/uploads/1/3/0/9/130969310/0ccb1.pdf
    • https://mufejuraziga.weebly.com/uploads/1/3/0/8/130814984/mafeguj_bumowomita.pdf
    • https://poximixej.weebly.com/uploads/1/3/0/7/130776069/f1caa55502ad43.pdf
    • https://static.s123-cdn-static.com/uploads/4465687/normal_5ff6941d5342f.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/rerinago/wow_wotlk_enhancement_shaman_pve_guide.pdf
    • https://s3.amazonaws.com/pafexegud/xuzesivumub.pdf
    • https://s3.amazonaws.com/xamibebulosaxug/fiat_barchetta_performance_parts.pdf
    • https://s3.amazonaws.com/jixerubowi/nfhs_volleyball_libero_tracking_sheet.pdf
    • https://s3.amazonaws.com/posufij/consider_phlebas_poem.pdf
    • https://s3.amazonaws.com/jagux/aurlie_laflamme_tome_9.pdf
    • https://s3.amazonaws.com/wiremeresegikon/air-_to-_air_tactics_and_combat_formations.pdf
    • https://s3.amazonaws.com/dofufiri/mupiv.pdf
    • http://bijalupukupami.rf.gd/53616892444.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://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e6c0.bin
bd21eaad11e5a91e48ede8cc79fa5d314fce602956d6d0bbac0588e1e43f410c
pdf-font-stream PDF embedded font (sfnt) at offset 0xE6C0 5308 bytes
font_01_sfnt_off0000f8dc.bin
aaf3ef8b235e544b0e39419d0f1e3d2d9551d5234c47c7cf8fff3d6d3d08694c
pdf-font-stream PDF embedded font (sfnt) at offset 0xF8DC 11148 bytes