Malicious PDF — malware analysis report

Static analysis result for SHA-256 871293c34df63ead…

MALICIOUS

PDF

76.1 KB Created: 2021-06-07 18:04:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: d8344e9de778a1c057d68159062994e3 SHA-1: 90a89ec33085885b7d81b508cac6f594ecaf716e SHA-256: 871293c34df63eadab69aa10da65c16425479500ac102526f1b1a2ee67f5147f
186 Risk Score

Malware Insights

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

The PDF document contains a large number of external links, many pointing to disposable hosting or link farms, indicating a likely attempt to drive traffic to malicious or phishing sites. The ClamAV detection and ML classifier strongly suggest malicious intent, classifying it as a phishing trojan. The document body, though heavily obfuscated, appears to be a lure related to food and carbohydrates, likely to trick users into clicking the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • 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 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.
  • 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://krisoc.ru/pbw?utm_term=lista+de+alimentos+con+carbohidratos+simples+y+complejos PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4379613/normal_604067e154748.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393499/normal_5fdb95a8d8eb0.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4487423/normal_5febd1d10f6a1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4462354/normal_6054f37352df5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490757/normal_603a62c420f4c.pdfIn PDF document text
    • https://mesakejaj.weebly.com/uploads/1/3/4/7/134754162/9f9816f.pdfIn PDF document text
    • https://mapimodedafibo.weebly.com/uploads/1/3/4/7/134708703/317126.pdfIn PDF document text
    • https://bipixexomalexu.weebly.com/uploads/1/3/4/3/134349320/devuwisuronax-jisibejibizifag-jenapeziziri.pdfIn PDF document text
    • https://zugatuwedi.weebly.com/uploads/1/3/0/8/130874050/1749910.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4401517/normal_6025567a53ce2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4457014/normal_604841bc70f56.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4425238/normal_6023b8bbde5a9.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://xesimisejek.pbworks.com/w/file/fetch/144500640/how_to_recover_deleted_chrome_history.pdfIn PDF document text
    • http://jutifakukap.pbworks.com/w/file/fetch/144483897/dalurire.pdfIn PDF document text
    • http://gamaxidad.pbworks.com/w/file/fetch/144800397/kafotakela.pdfIn PDF document text
    • http://togusan.pbworks.com/w/file/fetch/144427545/pezapekamezidobejejufapal.pdfIn PDF document text
    • http://fupimogevif.pbworks.com/w/file/fetch/144727524/bokobadoranolonim.pdfIn PDF document text
    • http://pidexuxok.pbworks.com/f/59269988520.pdfIn PDF document text
    • http://gibuwodebu.pbworks.com/w/file/fetch/144496197/nozuperotozonoxalozaso.pdfIn PDF document text
    • http://gibuwodebu.pbworks.com/w/file/fetch/144604449/how_to_read_hvac_ladder_diagrams.pdfIn PDF document text
    • http://legesir.pbworks.com/w/file/fetch/144742074/what_are_the_5_principles_of_nonverbal_communication.pdfIn PDF document text
    • http://gafuxexosaru.pbworks.com/f/couch_to_5k_running_plan_for_beginners.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e94a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE94A 5572 bytes
SHA-256: ec2caa2ff97a49e5dc831e7878d02fd60cd61708a7219c79aeb6547e6852b8b8
font_01_sfnt_off0000fc1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC1B 11760 bytes
SHA-256: 81046190ae073fa28af58459f60d62fa278c0277117ef574cf1df08661a5ebe7