Malicious PDF — malware analysis report

Static analysis result for SHA-256 99fea406800cfa71…

MALICIOUS

PDF

77.2 KB Created: 2021-09-18 00:31:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 220604ce6ecd3c8358f0644cee935a75 SHA-1: fc4224676b94f82b438bb6c18801e3df77c55221 SHA-256: 99fea406800cfa71cf738e99568515407ffaa88096eefbc02d6237ac680e365a
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised WordPress upload directories or disposable hosting, suggesting a link farm designed to redirect users. The ML_NYX_PDF_MALICIOUS heuristic and ClamAV detection strongly indicate malicious intent, likely to lure users to phishing or malware distribution sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://usateatop.com/_upload/files/xakowegadasatasudezetil.pdf In PDF document text
    • https://cultureresortpokhara.com/assets/userfiles/files/83748510224.pdfIn PDF document text
    • http://vinhthuan.vn/upload/files/wifajajizabugizuzarolonon.pdfIn PDF document text
    • https://www.burit.net/wp-content/plugins/formcraft/file-upload/server/content/files/16140901a11502---mivutiditupojax.pdfIn PDF document text
    • http://filtrydokoparek.pl/img/all/33891739405.pdfIn PDF document text
    • http://acetuitioncentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161356b1d90934---67574865922.pdfIn PDF document text
    • https://eijo.in/ckfinder/userfiles/files/74024943268.pdfIn PDF document text
    • http://plymouth-logs.co.uk/ckfinder/userfiles/files/83901766197.pdfIn PDF document text
    • http://henghuitong.com/jingkelun/userfiles/files/20210908223320.pdfIn PDF document text
    • http://www.egymast-segito.hu/uploaded/fck/file/68652824037.pdfIn PDF document text
    • http://bigcool.net/webroot/img/files/dikimijeragen.pdfIn PDF document text
    • http://medica-eg.com/userfiles/file/20807030847.pdfIn PDF document text
    • http://thechitay.com/uploads/userfiles/file/41133628747.pdfIn PDF document text
    • http://xn----otbb6ahq3d.xn--p1ai/ckfinder/userfiles/files/736189853.pdfIn PDF document text
    • http://urgentcarepb.com/userfiles/file/bebubu.pdfIn PDF document text
    • http://damutech.kz/upload/2021/09files/2109041521028775003e2ye.pdfIn PDF document text
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ea4a1bff50---videtavimupefonevive.pdfIn PDF document text
    • http://haphadoor.com/upload/files/44084078903.pdfIn PDF document text
    • http://otpetye.com/images/shared/file/82066296610.pdfIn PDF document text
    • http://colantuono.it/userfiles/files/37947754458.pdfIn PDF document text
    • http://hbisan.com/userfiles/file/68880942982.pdfIn PDF document text
    • https://travelinnsuites.com/nbloom/fckuploads/file/leraza.pdfIn PDF document text
    • https://12shio4.com/contents/files/31934729492.pdfIn PDF document text
    • http://felixefontesadvogados.com.br/ckfinder/userfiles/files/57046214022.pdfIn PDF document text
    • http://falconltd.pl/cache/file/89022956547.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=how+to+sync+my+android+phone+to+my+carPDF 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_off0000c508.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC508 18784 bytes
SHA-256: 91d3710da84d375a3e8ae0f103ae5fd20d503e05ca493eb01f8620fa7bc48186
font_01_sfnt_off0000f5a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5A3 10924 bytes
SHA-256: dfb207007ad41ef29596c5dfb931494e116c97c3258fa5afcc7a1890764f31ff
font_02_sfnt_off00010ed1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10ED1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1