Malicious PDF — malware analysis report

Static analysis result for SHA-256 1ef34b22e77c6bec…

MALICIOUS

PDF

87.0 KB Created: 2021-09-18 17:45:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 0342a7c3bf7aaeffc59377b96b9e7278 SHA-1: 640010f00f3ffef77ccccdd48fc23abf61b21a94 SHA-256: 1ef34b22e77c6becb52f15643a9ea7f314cc753ab42f4ffdf8260449f9a0ad93
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs that point to various domains, many of which appear to be compromised WordPress sites or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using numerous links on disposable hosting, suggesting an attempt to obscure the true malicious destination or to distribute various lures. The presence of these links strongly suggests the document's purpose is to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://archism.ru/uplcv?utm_term=vlc+android+mkv PDF link annotation
    • http://netinflux.net/userfiles/file/36577950901.pdfIn PDF document text
    • https://topinsolventa.ro/userfiles/file/12374962557.pdfIn PDF document text
    • https://avukat.dnsaktif.net/upload/files/niwosunowuta.pdfIn PDF document text
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16138b81a11e63---zotivasajoxa.pdfIn PDF document text
    • https://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/78a19a677484acc865335bbc564319c4/32806810383.pdfIn PDF document text
    • https://jdconstinc.com/ckfinder/userfiles/files/beguwim.pdfIn PDF document text
    • http://cappellastudio.it/userfiles/files/fesujijofizubet.pdfIn PDF document text
    • http://kasaitogo.com/uploads/files/27965543439.pdfIn PDF document text
    • https://rubenoferro.com/userfiles/file/jabizevasaf.pdfIn PDF document text
    • https://actaviaserica.org/board/file/files/vuvimepaxemoz.pdfIn PDF document text
    • http://esejsc.com/upload/files/35658846587.pdfIn PDF document text
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161395e5863c91---8932051462.pdfIn PDF document text
    • https://cashcruis.ru/wp-content/plugins/super-forms/uploads/php/files/5eb77515f68c17ff5c884e43d94e35a4/maluwebefiradok.pdfIn PDF document text
    • http://fresh-j.info/images/uploadedimages/file/68160892887.pdfIn PDF document text
    • http://specimport.by/files/files/9081220218.pdfIn PDF document text
    • http://dui-antidote.net/images/userfiles/file/5660851868.pdfIn PDF document text
    • http://perevodvnegiloifond.ru/pict/file/juzilolodapowe.pdfIn PDF document text
    • https://hospvetcentral.pt/site/upload/file/bedonijawibojamifo.pdfIn PDF document text
    • http://vakaruinzinerija.lt/userfiles/file/72229213115.pdfIn PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161376d1fedb33---72872952653.pdfIn PDF document text
    • https://betenenergy.com/sites/default/files/file/37187565575.pdfIn PDF document text
    • https://renault-service.com/userfiles/98830265329.pdfIn PDF document text
    • http://ilovestory.com/upload/file/69771022040.pdfIn PDF document text
    • http://kondicionery-lubertsy.ru/upload_picture/file/darosibawuzadojadujuvivi.pdfIn PDF document text
    • https://safetypadlocks.eu/eurostyl/photos/file/31713300282.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_off0000e87c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE87C 10260 bytes
SHA-256: dbc117bcccd509c64eebbc34667f071f6312993444cd2eefb0b8f48c671555fe
font_01_sfnt_off0000ff77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF77 20912 bytes
SHA-256: cafbf282d146dca63e7b8e9397956cb4ed903a0e02b60c1d1876058bf63afebd
font_02_sfnt_off00013625.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13625 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1