Malicious PDF — malware analysis report

Static analysis result for SHA-256 7863b31703e57fad…

MALICIOUS

PDF

80.2 KB Created: 2021-09-06 08:21:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 31916f7fc8585b5b5871500917c0be53 SHA-1: e50e85168662a4e9a1cf33e5f348a026a1e98cd8 SHA-256: 7863b31703e57fade21f2d62457d5892fe719b70b45a2343e4865897ac85cb98
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains numerous links pointing to compromised WordPress sites, which in turn host other PDF files. This indicates a link farm strategy likely used for phishing or distributing further malware. No scripts were extracted, but the presence of multiple external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly suggest a malicious intent to redirect users through a chain of compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://crysiq.ru/uplcv?utm_term=spectroscopy+problems+pdf PDF link annotation
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/88543c34dfcc37b419d4020590371ed0/74895299092.pdfIn PDF document text
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/5df2cb14bcf6054937ff0cce5ad70579/88293622827.pdfIn PDF document text
    • https://airshow-bg.com/file/63176039630.pdfIn PDF document text
    • http://kancelaria-perfect.pl/app/webroot/media/files/94202159811.pdfIn PDF document text
    • http://solarexperten.ch/fckeditor/editor/images/file/22762670613.pdfIn PDF document text
    • http://firanywiktoria.pl/uploads/editor/file/dafifopamoged.pdfIn PDF document text
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b73f5721aeb---86443541541.pdfIn PDF document text
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1609aa72c10e20---xapajugadunanazemim.pdfIn PDF document text
    • http://beachfirebrands.com/userfiles/file/xerel.pdfIn PDF document text
    • http://telegid.tv/userfiles/files/ziwegobivuxas.pdfIn PDF document text
    • http://geobigoni.it/userfiles/files/70113843086.pdfIn PDF document text
    • https://psfund.org/public/uploads/files/cms_files/1734272638.pdfIn PDF document text
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160847c43b8dfe---27443697527.pdfIn PDF document text
    • http://restauraceeverest.cz/userfiles/file/vurimida.pdfIn PDF document text
    • https://www.mnspineandsport.com/wp-content/plugins/super-forms/uploads/php/files/35c7e221836a451fb7bcba4cd7164206/mixopazesaxalesazijapazof.pdfIn PDF document text
    • https://www.scilights.com/wp-content/plugins/super-forms/uploads/php/files/3cdd70499ebe92def9ad53e2f4e41fec/61955572625.pdfIn PDF document text
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/1r6lmuo6keb8fm3euaubh8g1t2/81296429284.pdfIn PDF document text
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160f3992b68059---27821894765.pdfIn PDF document text
    • http://berbun.com/user_img/file/54093471454.pdfIn PDF document text
    • http://tz5168.com/uploadfile/image/2021/06/06/file/20210606_095230_136.pdfIn PDF document text
    • https://bangkoksolarpower.com/syner_upload/images/files/sopimek.pdfIn PDF document text
    • http://sbkf.org/files/files/mawulagujiwi.pdfIn PDF document text
    • http://creationart.hu/files/file/8660135129.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_off0000d55b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD55B 17432 bytes
SHA-256: 410588c9d28da7fe16739bb520d88a76b32a2fc2328075dba6c3c09187e4f4e3
font_01_sfnt_off000102a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102A3 10752 bytes
SHA-256: e5b8b88a0a33cd1e9d5ffed52a3090660bc29a2f4134e87e579a23c6923b8661
font_02_sfnt_off00011b2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B2F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

Open this report in the interactive analyzer, or submit your own file for analysis.