Malicious PDF — malware analysis report

Static analysis result for SHA-256 160f5a8370316d04…

MALICIOUS

PDF

79.7 KB Created: 2021-09-15 14:47:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 0c835b7dafc6e9285cdbf634c709e20b SHA-1: 7e7555b10846872a5fa33022089c6b022dfd9301 SHA-256: 160f5a8370316d0468dd95e636ccdd7c6a66f9ca1833fac03cd898f71d62155d
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, with a specific detection name indicating phishing and trojan activity. The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic further supports this, indicating a tactic to obscure the true destination. No scripts were extracted, but the overall structure points to a phishing or malware distribution lure.

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=words+their+way+digraph+sorts+pdf PDF link annotation
    • http://dotykbylinky.sk/_subory/subory/63436557126.pdfIn PDF document text
    • http://fujavietnam.com/images/Download/mevawanajusenote.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/161347a45e8bf1---30843949800.pdfIn PDF document text
    • http://busankid.com/webfiles/board/file///xuterezego.pdfIn PDF document text
    • http://laihoawedding.com/app/webroot/upload/files/ramujevobaz.pdfIn PDF document text
    • https://buddhaart.in/userfiles/file/gotefixubu.pdfIn PDF document text
    • https://burlingame.com/wysiwygfiles/file/nuxezupobafinonen.pdfIn PDF document text
    • https://betalinktech.com/blmedia/file/82380840332.pdfIn PDF document text
    • https://girisimhaber.com/uploads/file/90285401947.pdfIn PDF document text
    • https://www.harnoordesigns.com/wp-content/plugins/super-forms/uploads/php/files/7f0bb0d29bd6ee1b1db79151f40c60c5/31559774800.pdfIn PDF document text
    • https://www.luxboss.com/ckfinder/userfiles/files/kudadekisazuximube.pdfIn PDF document text
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/16140208f4a59e---35316616882.pdfIn PDF document text
    • https://www.tahitotfaluovodak.hu/ckfinder/userfiles/files/82628652327.pdfIn PDF document text
    • http://notariocprietoa.com/notaria/documentos/files/74819184709.pdfIn PDF document text
    • https://dichvumayphoto.vn/webroot/img/files/zarevemijokoverekapapeb.pdfIn PDF document text
    • http://oipipleszno.pl/userfiles/file/29912688035.pdfIn PDF document text
    • http://preprod.app-nomads.com/ugecam/admin/ckfinder/userfiles/files/rukaxewepamutoso.pdfIn PDF document text
    • https://ski-valloire.com/ckfinder/userfiles/files/90945048162.pdfIn PDF document text
    • https://muachungbaohiem.com/uploads/userfiles/file/powisilepomu.pdfIn PDF document text
    • https://hotelcorona.ro/files/xitaruxuzupedoma.pdfIn PDF document text
    • https://pima-alarms.net/slicice/file/32487375603.pdfIn PDF document text
    • https://cdmsig2.com/ckfinder/userfiles/files/12919314891.pdfIn PDF document text
    • http://profil-metall.de/content/uploads/file/63625453354.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/87484139042.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_off0000c591.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC591 22236 bytes
SHA-256: b38c9977d45e830906c4fd2ed70e4e141325032a628ed2ec108ecd24f87e817a
font_01_sfnt_off0000ff10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF10 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011727.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11727 10820 bytes
SHA-256: 7e28b8d85a965c05700452776fd02d8a731d5442b13362a6e9bfb234509021cd