Malicious PDF — malware analysis report

Static analysis result for SHA-256 c53902cbcb55f55f…

MALICIOUS

PDF

69.5 KB Created: 2021-09-26 15:50:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: d213e5656d2bd634f54271e11b59158c SHA-1: 63a343d18f56e6b95bcdb316337b5c030b061fb4 SHA-256: c53902cbcb55f55f4af7a3b374b3d3db990f3afe61068ad474ca67792218ff34
126 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan payload. It contains numerous embedded URLs pointing to disposable domains, characteristic of a link farm designed to redirect users to malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically flags this behavior, suggesting the document's primary purpose is to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://catamma.ru/uplcv?utm_term=how+to+close+open+windows+on+android+phone PDF link annotation
    • http://jiangsutravel.kr/userfiles/files/20210913_194809.pdfIn PDF document text
    • https://weboonline.com/ckfinder/userfiles/files/56577115053.pdfIn PDF document text
    • http://gadkowski.pl/repository/filemanager/file/fewidezabuxir.pdfIn PDF document text
    • http://a1-automotivegroup.com/upload/files/sanumusofakowaguxuv.pdfIn PDF document text
    • http://interroadholland.nl/userfiles/file/pewokakin.pdfIn PDF document text
    • https://zhongzing.com/uploads/files/202109222114526587.pdfIn PDF document text
    • http://investgeorgia.ge/userfiles/file/jijezapakawifunepe.pdfIn PDF document text
    • http://duocthientam.com/uploads/ckfinder/files/58990806761.pdfIn PDF document text
    • http://abwingsjanaf.com/uploads/files/73471899541.pdfIn PDF document text
    • http://cathugo-yachts.de/res/wysiwyg/file/fimuzedisusemapubuge.pdfIn PDF document text
    • https://yar-net.ru/userfiles/file/26513230640.pdfIn PDF document text
    • https://www.hinkler.com.au/application/third_party/ckfinder/userfiles/files/sipinexupuwomuzonid.pdfIn PDF document text
    • https://bisleriuber.genefied.co/ckfinder/userfiles/files/badugupijafijulojefu.pdfIn PDF document text
    • http://rund.cz/UserFiles/File/15002659644.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/069b71c702fce3ab3a8101abeba301c1/6755171823.pdfIn PDF document text
    • http://3bbb.fr/ckeditor/upload/files/6113173393.pdfIn PDF document text
    • http://smirna.pl/files/file/bepot.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/161328ff30af8b---goxetiminuwogos.pdfIn PDF document text
    • http://onmamtour.com/FileData/ckfinder/files/20210912_62534080C0BE16D9.pdfIn PDF document text
    • http://varosom.hu/userfiles/files/kokesonubemozipaja.pdfIn PDF document text
    • http://fabriziocar.it/userfiles/files/duwogufuwuwotemenep.pdfIn PDF document text
    • https://learnrkbin.jugalbandiresearch.com/ckfinder/userfiles/files/zalikozisasiwe.pdfIn PDF document text
    • http://adveotec.com/img/file/mulelunowedowu.pdfIn PDF document text
    • http://speckrepej.com/upload/file/loxarawog.pdfIn PDF document text
    • https://successalpha.team/upload/files/61483905552.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_off0000b2f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2F9 10688 bytes
SHA-256: 2cd5e8773ecade79f9c7b362ff955f6b3946283a664e1f142c2ea8f6fc2d9428
font_01_sfnt_off0000cb6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB6F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e381.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE381 14520 bytes
SHA-256: 1858982b046bb49c48ed82bf347b8d057b377c1514a7b39bebaf266f0fc8015b