Malicious PDF — malware analysis report

Static analysis result for SHA-256 851bc3819b53ad16…

MALICIOUS

PDF

106.0 KB Created: 2021-05-12 19:21:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 80c3dc03aea69d05bd6ea622e4e61349 SHA-1: 69376914f6c17404a62ed18f020b2b501db9624d SHA-256: 851bc3819b53ad16e51202905b8a3a628321ecf24810ff0f19e6dc08d6da5e99
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 disposable domains, indicating a link farm or phishing operation. The ML classifier and ClamAV detection strongly suggest malicious intent, specifically identified as a phishing trojan. While no scripts were explicitly extracted, the PDF structure and numerous external URLs are indicative of an attempt to redirect users to malicious sites, likely for credential harvesting or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://pelibifir.ru/strik?utm_term=can+a+guardian+ad+litem+recommend+sole+custody PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4373509/normal_5fcc0c5ac3aa7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4370746/normal_601be10133fb2.pdfIn PDF document text
    • http://jewofuvivonog.getenjoyment.net/76863190302.pdfIn PDF document text
    • https://webapifupa.weebly.com/uploads/1/3/4/7/134706955/boratix.pdfIn PDF document text
    • https://fubexomufepa.weebly.com/uploads/1/3/4/8/134850999/1d2733d95.pdfIn PDF document text
    • http://borejukeluteva.mygamesonline.org/gejotitetulif.pdfIn PDF document text
    • https://kaxukododeregoz.weebly.com/uploads/1/3/0/9/130969338/tuzuzalapuvu.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4383913/normal_5febc6b85c1cc.pdfIn PDF document text
    • http://vimoroketoburiv.22web.org/advanced_level_biology_notes_download.pdfIn PDF document text
    • https://bifezogutagu.weebly.com/uploads/1/3/4/5/134598372/eed59daba9.pdfIn PDF document text
    • https://jajaleregonu.weebly.com/uploads/1/3/4/2/134235513/5771999.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4486778/normal_5feb7af254abb.pdfIn PDF document text
    • http://rigopimoter.iblogger.org/chakra_cleansing_meditation.pdfIn PDF document text
    • https://durapafived.weebly.com/uploads/1/3/1/4/131438767/3140859.pdfIn PDF document text
    • https://bofazereb.weebly.com/uploads/1/3/4/6/134675062/1512261.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4427273/normal_6035d54156602.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4368972/normal_5ff98eaa9d1f7.pdfIn PDF document text
    • https://wevikafajaxa.weebly.com/uploads/1/3/1/1/131164556/1238751ab67.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://fikumowo.rf.gd/33670192684.pdfIn PDF document text
    • http://kojodidekojamu.rf.gd/xejubinab.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_off0001639e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1639E 5268 bytes
SHA-256: 5777b7668503bcff7343884346c4cbbf5e7f2097ee65ffb8ed403a6f964c5cac
font_01_sfnt_off00017575.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17575 10884 bytes
SHA-256: e15ddb38fc1df87cb0889c9b30917f48b169df056f5b717b6e1c752a5b1d5c82