Malicious PDF — malware analysis report

Static analysis result for SHA-256 4efa50d9a0d135b5…

MALICIOUS

PDF

82.9 KB Created: 2021-09-14 11:02:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 35b7d1825cc45971ac0e7a4c9f23dbe3 SHA-1: f306c6340e8827ab8418995b56408165f1c6b442 SHA-256: 4efa50d9a0d135b5fde39fb311ebc55f033c4fb51fc9ce256d5e1167332b965d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, with heuristics indicating it functions as a link farm. The embedded URLs, despite some being marked as benign, contribute to the overall suspicious nature by directing users to potentially harmful sites. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests a deliberate attempt to create a large number of links on disposable hosting, a common tactic for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://dwitunggaljaya.com/sitefiles/file/reposinetefigevufugikar.pdf In PDF document text
    • http://tribo.kz/userfiles/File/mukusoku.pdfIn PDF document text
    • http://anais.terminarz.online/kosmetyczka/krakow/files/87017923561.pdfIn PDF document text
    • http://duonglaohanoi.com/userfiles/file/pewesebetedejupaf.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/josaxas.pdfIn PDF document text
    • http://ttccid.com/userfiles/file/dudiw.pdfIn PDF document text
    • https://omnistopbollards.com/application/third_party/ckfinder/userfiles/files/kipubodo.pdfIn PDF document text
    • http://novosib-sport.ru/ckfinder/userfiles/files/50173958547.pdfIn PDF document text
    • http://immobiliareborghi.com/userfiles/files/54033814664.pdfIn PDF document text
    • http://sbriz.ru/userfiles/file/81546169048.pdfIn PDF document text
    • http://loscogliodifavignana.it/userfiles/files/sugaketezokukijod.pdfIn PDF document text
    • https://bonvoyageindia.in/ckfinder/userfiles/files/wetupijepinadug.pdfIn PDF document text
    • https://cfacgroup.com/uploads/FCK_files/file/nusuxumugobumosexidiluluw.pdfIn PDF document text
    • http://maschimaurizio.it/userfiles/files/fijuvu.pdfIn PDF document text
    • http://sakem.org/userfiles/files/xosasiwatedotonudazerer.pdfIn PDF document text
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/16136d5a5c4f13---vosibovamobomatowugobopif.pdfIn PDF document text
    • https://birudongker.com/contents/files/rupewimijuxojaj.pdfIn PDF document text
    • https://landbondcorten.com/attachment/file/c1aa2b64d158767b4d95b34236f5fd03.pdfIn PDF document text
    • http://bangiyaparishadtoronto.ca/bpt/editor/uploadfiles/jominorovox.pdfIn PDF document text
    • https://saigonservices.vn/images/uploads/files/kodotuwomimevipaxizebomup.pdfIn PDF document text
    • https://karolinanowak.com/userfiles/file/lizofuvasanutozimoledep.pdfIn PDF document text
    • https://nikosdimos.gr/userfiles/file/sajonuzegobamopagukamav.pdfIn PDF document text
    • https://telewebmarketing.com/FCKeditor/file/8377760602.pdfIn PDF document text
    • http://nwatchonline.com/userfiles/file/bewepabuladawovagoviniri.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=wlan+einstellungen+zur%C3%BCcksetzen+androidPDF 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_off0000d839.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD839 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f050.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF050 10980 bytes
SHA-256: ba993e2716cb694509794f40895f210252d4eb19aa60940c66fb937ec788b676
font_02_sfnt_off00010982.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10982 19636 bytes
SHA-256: d5a2d3c57c85b69aa21f8620f1b543661c37ca38c3dcac81645866695c4ed766