Malicious PDF — malware analysis report

Static analysis result for SHA-256 819bce5ee970c9ea…

MALICIOUS

PDF

74.9 KB Created: 2021-09-08 23:48:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7d6bb1f7ea2f1c1db079bba020a97f3c SHA-1: c099c716ae1612cf04afa68addfccf1f3c3b3927 SHA-256: 819bce5ee970c9eab3772924e7db40616ef0524f932ab80efab0b070c468d771
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. Numerous heuristics indicate the PDF functions as a link farm, directing users to various domains, many of which appear to be compromised WordPress sites or disposable hosting. The embedded URLs suggest an attempt to redirect users to potentially malicious content, consistent with phishing or malware distribution tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://synerhu.ru/uplcv?utm_term=ser+invisible+en+whatsapp+android
    • http://propertiesforrent.com/userfiles/file///gupivovinotenisu.pdf
    • http://akcihlar.cz/userfiles/file/mafuvomuv.pdf
    • http://budaors.varosom.hu/userfiles/files/vozujorape.pdf
    • https://www.sidertest.it/wp-content/plugins/formcraft/file-upload/server/content/files/16134fdfccd647---nafefafevojijat.pdf
    • http://cmorshomecareassociates.org/uploaded_files/userfiles/files/2906246272.pdf
    • http://sofia-es.tokyo/yamituki-n/uploads/files/xapovebuz.pdf
    • http://maynenkhiinverter.com/media/ftp/file/91449769647.pdf
    • https://stakeoutllc.com/wp-content/plugins/super-forms/uploads/php/files/c3433c0c3b0d52f4ba91b4b09d50059f/42877496394.pdf
    • http://vizugy.hu/uploads/files/bimapaxepesulefo.pdf
    • http://opgzvh.hr/upload/file/71485517672.pdf
    • https://kawanmto.net/contents/files/novunisenolupodarudozopi.pdf
    • https://8foro.exceltur.org/exceltur_nuevo/ckfinder/userfiles/files/jaguso.pdf
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/161367414c7dfa---vanase.pdf
    • http://arenabilardo.com/data/_files/lelijezovivapasibub.pdf
    • http://terminsk.by/pics/files/84671473312.pdf
    • http://avvocatoandreabruschi.it/userfiles/files/17990844515.pdf
    • https://ivfnna.gr/wp-content/plugins/super-forms/uploads/php/files/6ef3fff491d48487cc41931d8d9b883e/tuzisezuxelululekosido.pdf
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/161308f2e43036---peripoku.pdf
    • https://www.bluegreenshouseboats.in/wp-content/plugins/formcraft/file-upload/server/content/files/16137aee15105b---28133029451.pdf
    • https://vgi-vn.vn/app/webroot/img/files/12122233012.pdf
    • https://lochoanggia.com/upload/files/bepotapitaguvu.pdf
    • https://valleyrentals.com/userfiles/file/sisubeposutowamaxar.pdf
    • http://pretaporter-pegah.com/userfiles/file/fedepu.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c1cc.bin
ccce054953253d03736751632d39c8078f4219dd9bb7948213f4b1eccdbe4cd2
pdf-font-stream PDF embedded font (sfnt) at offset 0xC1CC 16916 bytes
font_01_sfnt_off0000ed74.bin
68cbb10f6e1031ed87539e4a616c36118b08845c93c6af283741e75282cade52
pdf-font-stream PDF embedded font (sfnt) at offset 0xED74 10856 bytes
font_02_sfnt_off00010647.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10647 16792 bytes