Malicious PDF — malware analysis report

Static analysis result for SHA-256 bff71def340d6e20…

MALICIOUS

PDF

84.1 KB Created: 2021-09-17 18:45:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 6e826ed27e77f619b20284b283c6d996 SHA-1: 77d40b643a03a51932c9e60c7c0b21e6bed92890 SHA-256: bff71def340d6e20e2c0fb8d3a891719e15ae6ec369967f742c30fd64effa6be
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ML classifiers and ClamAV as malicious, with heuristics indicating it functions as a link farm on disposable hosting. The embedded URLs, such as 'https://motty-etai-sharon.com/files/files/31671308131.pdf', are likely intended to redirect users to malicious sites. The document body is heavily obfuscated and appears to be generated content rather than user-readable text.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 5

  • 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://motty-etai-sharon.com/files/files/31671308131.pdf In PDF document text
    • http://sh-songshi.com/admin/upimg/file///87949560072.pdfIn PDF document text
    • http://furkansigorta.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/161332784bcc8a---diwasidusibivegawabax.pdfIn PDF document text
    • http://www.miamiairportlimo.net/wp-content/plugins/formcraft/file-upload/server/content/files/16134e8bf27ece---53540494794.pdfIn PDF document text
    • http://kunas.lt/app/webroot/uploads/files/89115830427.pdfIn PDF document text
    • https://www.hkfew.org.hk/ckfinder/userfiles/files/savimiguwapixitoradirobi.pdfIn PDF document text
    • https://ozmutludokum.com/userfiles/file/35531426047.pdfIn PDF document text
    • https://samowar.me/upload/file/77797142548.pdfIn PDF document text
    • https://meganimal.pt/site/upload/file/kozed.pdfIn PDF document text
    • http://195exim.com/datas/files/65842309411.pdfIn PDF document text
    • http://dlabiura.kbo.pl/ckfinder/userfiles/files/wofalanevaf.pdfIn PDF document text
    • http://officegate.biz/admin/fck_upload/file/74275862184.pdfIn PDF document text
    • https://vestol.bg/files/file/76869432091.pdfIn PDF document text
    • http://bronia.org/userfiles/file/88168798193.pdfIn PDF document text
    • http://emannsltd.com/userfiles/72850070626.pdfIn PDF document text
    • http://tvoirostov.ru/ckfinder/userfiles/files/wemolevudobubavoluxuze.pdfIn PDF document text
    • https://vettercycles.ch/userfiles/files/94289272.pdfIn PDF document text
    • http://beverly.kopanramen.com/uploads/files/wefedoxikubu.pdfIn PDF document text
    • http://yesilderecine.com/admin/editor_resim/file/kulisuj.pdfIn PDF document text
    • http://arsvet.ru/img/upload/95584251088.pdfIn PDF document text
    • https://bandai-k.com/userfiles/file/82017007563.pdfIn PDF document text
    • http://philipp-haberland.de/images/upload/file/2993085915.pdfIn PDF document text
    • http://halmar.info/userfiles/file/kegexudinedusewi.pdfIn PDF document text
    • http://stigstudiotecnico.it/userfiles/files/noboxilixekigu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=instagram+likes+followersPDF 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_off0000e399.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE399 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fbb0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBB0 10684 bytes
SHA-256: 10feec66ff3b501a1755fabaef94c117ce4651a242e9e618bd20f966fab5dea2
font_02_sfnt_off00011439.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11439 18252 bytes
SHA-256: da1cf832bb926947b9b8eb4c04c7c30430fad7a5fd165514baedf7aa4ff686ec