Malicious PDF — malware analysis report

Static analysis result for SHA-256 831b6cd68510c454…

MALICIOUS

PDF

70.9 KB Created: 2021-01-12 15:40:24 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 8bce816704c45251c94aee04beb70bb1 SHA-1: b146b355f5f4e91c13bfc822bc54979d76abb3fb SHA-256: 831b6cd68510c45441fe5ba1c611a7ef41c9f534e836ac5f7e715037cd6bdf4b
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many pointing to other PDF documents, indicating a link farm or SEO manipulation tactic. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or distributing further malware. While no scripts were explicitly extracted, the presence of numerous external URLs and the heuristic 'PDF_SEO_LINK_FARM' point towards a malicious document designed to lure users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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
  • 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://trafftec.ru/123?utm_term=how+to+read+aeronautical+chart
    • https://wijodemarivupi.weebly.com/uploads/1/3/4/8/134861972/ramosikogimamur-dajurisa-viraf-fogoruweropoz.pdf
    • https://site-1175994.mozfiles.com/files/1175994/zojobavutunufibusotu.pdf
    • https://tokenabasefegaw.weebly.com/uploads/1/3/3/9/133999291/8866398.pdf
    • https://norigawe.weebly.com/uploads/1/3/3/9/133988483/kazaxojogozaw.pdf
    • https://fubudebuz.weebly.com/uploads/1/3/2/7/132712336/busafevedadisep_dokukabux.pdf
    • https://padefogufagabak.weebly.com/uploads/1/3/4/7/134714354/pitiwuzaxivumo-kuvifunawaxaj.pdf
    • https://bidutujube.weebly.com/uploads/1/3/4/4/134403342/jewom.pdf
    • https://site-1168136.mozfiles.com/files/1168136/pancake_the_game.pdf
    • https://nobujowufovipi.weebly.com/uploads/1/3/4/6/134636268/wobatu.pdf
    • https://muxalibozut.weebly.com/uploads/1/3/4/7/134718599/rebexut-pidoguvuvu.pdf
    • https://taruzalo.weebly.com/uploads/1/3/5/3/135398133/991a91417a.pdf
    • https://vuveporejar.weebly.com/uploads/1/3/2/6/132695394/vesokudosidozezoge.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/vibuvomomuv/elgin_westminster_chime_clock_manual.pdf
    • https://s3.amazonaws.com/suzujewa/tadaxara.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_off0000da0b.bin
58ccddf762cc28619b2b783fb7cfc44b6f91652acbed133d32ff0b1678d0a92e
pdf-font-stream PDF embedded font (sfnt) at offset 0xDA0B 4900 bytes
font_01_sfnt_off0000eaba.bin
0681a2698ddcc37ff4b1fc8f52263dd3caee89bb23e16391aece8d05e4e62a94
pdf-font-stream PDF embedded font (sfnt) at offset 0xEABA 10440 bytes