Malicious PDF — malware analysis report

Static analysis result for SHA-256 c11681b5748fe2dd…

MALICIOUS

PDF

79.7 KB Created: 2021-09-18 07:26:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: ac185f35693296f8585cd80319ef1fba SHA-1: 422fbbeb372d00797115156b0a3c6bc010df1433 SHA-256: c11681b5748fe2dddf6e1c9fce466c8b09e9a1f056eca13a1f877cce9406521d
146 Risk Score

Malware Insights

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

The PDF was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier indicating maliciousness. The presence of a 'link farm' heuristic and numerous embedded URLs pointing to potentially disposable domains suggests a phishing or malware distribution attempt. The document body was unreadable, but the overall structure and URL patterns strongly indicate a malicious intent to redirect users to harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://auf.vn/wp-content/plugins/super-forms/uploads/php/files/lbnrcnpv9hqng5dpltd625c1f1/53195956245.pdf In PDF document text
    • https://blugarden.eu/file/lopisenapexaxun.pdfIn PDF document text
    • http://kabaretyimpresariat.pl/Upload/file/benolijezijesij.pdfIn PDF document text
    • https://marblo.com/app/webroot/img/files/pokudikumosuxujuwab.pdfIn PDF document text
    • http://puntolinea.org/userfiles/files/suwuwobowemerenoderifes.pdfIn PDF document text
    • https://chongtham68.com/app/webroot/uploads/files/jazivutopimire.pdfIn PDF document text
    • http://tasarimak.com/ckfinder/userfiles/files/namevijefudatojutiwifu.pdfIn PDF document text
    • https://hospvetcentral.pt/site/upload/file/58736907003.pdfIn PDF document text
    • https://at1apigroup3.com/contents/files/bixivijamokibaxaseg.pdfIn PDF document text
    • http://fazendasaojudastadeu.net/fotosempresa/files/52492288212.pdfIn PDF document text
    • https://cakkue.com/contents/files/miwidet.pdfIn PDF document text
    • http://sweatrinserepeat.com/ckfinder/userfiles/files/22043163601.pdfIn PDF document text
    • http://sporteambiente.it/ckfinder/userfiles/files/45679666270.pdfIn PDF document text
    • http://artpolyclinic.com/file/files/48748922003.pdfIn PDF document text
    • http://votava2.altrodesign.eu/ckfinder/userfiles/files/xogidibomoponizo.pdfIn PDF document text
    • https://ego-sofa.tw/uploads/files/202109171826369645.pdfIn PDF document text
    • https://trieurodata.ro/images/file/belevovaz.pdfIn PDF document text
    • http://www.dfdtrading.sk/ckfinder/userfiles/files/fizevowovux.pdfIn PDF document text
    • https://jin-hung.com/userfiles/file/doxibozaluruvafofun.pdfIn PDF document text
    • http://damutech.kz/upload/2021/09files/210907201638215189eyg0v.pdfIn PDF document text
    • http://pet.nfe.go.th/m_site/ckfinder/userfiles/files/debojegerewuzidu.pdfIn PDF document text
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/161384b10708a5---61588398737.pdfIn PDF document text
    • http://starfishdowney.com/uploads/files/79320330855.pdfIn PDF document text
    • http://lingeriedediva.com/UploadFile/file/2021091809011373499.pdfIn PDF document text
    • https://cdmsig.com/ckfinder/userfiles/files/tafinin.pdfIn PDF document text
    • http://3e-recycling.ru/app/webroot/filesfiles/vunofejunokipekepukovabag.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=online+onenote+loginPDF 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_off0000d5ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5CA 9880 bytes
SHA-256: 5cca2278207fc56cfee9a0d61986918c2f3c26dd422963ab8fb8c63ac6639d00
font_01_sfnt_off0000eb9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB9F 17292 bytes
SHA-256: 4650b486129a8fb017030f310692c84a8328091647cb3a5d92a886443466fcaa
font_02_sfnt_off000118c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118C1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1