Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7629855aadfde64…

MALICIOUS

PDF

82.7 KB Created: 2021-09-13 19:35:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 0b316a38d75990f9ed4b9760b1f90f3f SHA-1: 83c01530e6e44e720da2da9717e348026a945bf4 SHA-256: a7629855aadfde64202e670774be663b138592f3e945270fb072f25fd7f87a98
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a phishing or trojan payload. It contains numerous embedded URLs that function as a link farm, directing users to download software, with one prominent URL being https://chcial.ru/uplcv?utm_term=korean+pubg+download+apk+and+obb. The presence of multiple disposable hosting links further supports the malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://chcial.ru/uplcv?utm_term=korean+pubg+download+apk+and+obb PDF link annotation
    • http://rambud.pl/uploaded/file/xosiboze.pdfIn PDF document text
    • http://www.sindafaz.com.br/admin/editor/ckfinder/userfiles/files/25974664506.pdfIn PDF document text
    • http://thietbikhachsanvinhhung1.com/upload/files/tikololaxaketij.pdfIn PDF document text
    • http://www.aamuhsv-madisonalumni.org/files/files/bejewagowogefun.pdfIn PDF document text
    • https://dursunguney.com/userfiles/files/25979690818.pdfIn PDF document text
    • https://szabobuszrendeles.hu/files/files/90332209945.pdfIn PDF document text
    • http://katour.ru/admin/ckfinder/userfiles/files/welakuvaj.pdfIn PDF document text
    • http://badgerhillfarm.uk/kumim.pdfIn PDF document text
    • https://tradingcall.in/ckfinder/userfiles/files/mogaziput.pdfIn PDF document text
    • https://www.lucaslobker.com/minor/ckfinder/userfiles/files/pozapezedofutosukaxifoji.pdfIn PDF document text
    • http://lambanghieuquangcaogiare.net/vietkiendo/upload/file/69051298675.pdfIn PDF document text
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e19d62a249---xipefofa.pdfIn PDF document text
    • http://livelyway.com/ckfinder/userfiles/files/91777393472.pdfIn PDF document text
    • https://www.mozartcantat.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16138e21a0c33f---36070495460.pdfIn PDF document text
    • http://hosungtour.net/FileData/ckfinder/files/20210913_17C0CF85E78D752B.pdfIn PDF document text
    • https://luminex.pl/upload/file/pufupe.pdfIn PDF document text
    • http://registermycompany.in/admin/userfiles/file/17517312838.pdfIn PDF document text
    • http://equipociclistaugeraga.com/ciclistas/userfiles/file/vubufujorapotovetazipawad.pdfIn PDF document text
    • http://mensagemcrista.com.br/ckfinder/userfiles/files/6835084941.pdfIn PDF document text
    • https://ljlconst.com/admin/images/file/57390935826.pdfIn PDF document text
    • https://sankaibearing.com/userfiles/files/78403489101.pdfIn PDF document text
    • https://kccegis.com/upfiles/content/file/20210909032215.pdfIn PDF document text
    • http://golfproradost.cz/webpagebuilder/ckfinder/userfiles/files/36282221977.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_off0000dd66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD66 18468 bytes
SHA-256: a9fb59be2666bf9828da1904a7306cc13c8b0d21a5ec69194d95ac2e7c26147c
font_01_sfnt_off00010d5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D5B 10620 bytes
SHA-256: 2e1fd766eb27ce11535f4393ee7b02d4635a5b61cf2b57475193d52506ec77ca
font_02_sfnt_off0001254a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1254A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1