Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef46ae0905caf66c…

MALICIOUS

PDF

81.6 KB Created: 2021-09-09 18:02:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 4f8cfbce0fcac9ef4fe30baf09fd23cd SHA-1: 599601d936d0bc325a2b1f2cbd47b577c4491729 SHA-256: ef46ae0905caf66c913e8e6b3b15bad4c9a25236e0bcbec13e74a38e381b2aa6
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which are hosted on disposable domains, indicating a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://queure.ru/uplcv?utm_term=block+in+app+ads+android PDF link annotation
    • http://peknanevesta.sk/media/file/727755042.pdfIn PDF document text
    • https://ceccarbotosani.ro/userfiles/file/14925727266.pdfIn PDF document text
    • https://kaemsp.org/upload/editor/file/radebixanulavovor.pdfIn PDF document text
    • http://spreewaldatelier.de/img/editor/file/41392415607.pdfIn PDF document text
    • http://lucidarepavimentimarmogenovaealessandria.it/userfiles/files/95017124499.pdfIn PDF document text
    • http://pass38.com/images/contentimages/files/49494145291.pdfIn PDF document text
    • https://anakmeong.com/contents/files/naguzavujajel.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613407353d3ef---18524848759.pdfIn PDF document text
    • http://feach.ie/images/uploads/file/31221938361.pdfIn PDF document text
    • http://zhongjiukeji.com/upload_fck/file/2021-9-3/20210903041659867075.pdfIn PDF document text
    • http://alajwakh.com/uploaded_files/userfiles/files/54323494765.pdfIn PDF document text
    • https://www.solucionaesp.com/ckfinder/userfiles/files/31796640129.pdfIn PDF document text
    • http://cayxaotamphan.net/userfiles/image/file/simodomizuda.pdfIn PDF document text
    • http://yer-krasnodar.ru/ckfinder/userfiles/files/susutekak.pdfIn PDF document text
    • http://playonathletics.com/userfiles/file/xixabumegaborukoru.pdfIn PDF document text
    • http://stihoplet.by/upload/editor/files/40500187501.pdfIn PDF document text
    • http://turagent007.ru/userfiles/file/59079489045.pdfIn PDF document text
    • https://uslugiinzynierskie.eu/eurostyl/photos/file/relel.pdfIn PDF document text
    • http://aotem.com/data/home/qxu1780220113/htdocs/uploadfile/files/5309974018.pdfIn PDF document text
    • http://polymer-optix.de/userfiles/file/varapemomuperawisugese.pdfIn PDF document text
    • http://stroyindustry.com/userfiles/file/99092403771.pdfIn PDF document text
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136d71a97333---koxetonizive.pdfIn PDF document text
    • http://devitohomesorlando.com/userfiles/files/54208582563.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://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_off0000dca5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCA5 10424 bytes
SHA-256: d9a9c7cb7bf36da9dab2425430efb2a928c81c81de4c21ace7249a8cf99596b7
font_01_sfnt_off0000f458.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF458 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010c6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C6A 17084 bytes
SHA-256: 80831772c5c9994003b49741b3690c92444a51942190e0ace9d119c46277f232