Malicious PDF — malware analysis report

Static analysis result for SHA-256 b916f6594e18b749…

MALICIOUS

PDF

74.4 KB Created: 2021-09-24 14:48:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: d61f77142e00acc6c3aa524058b553fd SHA-1: df27284af1bb5d11b5723a14df081aa5e3dbdcdb SHA-256: b916f6594e18b749789a401dc1b308acbf802b1825c918fb2bfc6f5928647dcf
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on compromised WordPress installations or disposable domains, indicating a link farm designed for malicious purposes. The ClamAV detection and ML classifier strongly suggest this PDF is malicious, likely a phishing or malware distribution lure. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://krisoc.ru/uplcv?utm_term=diskdigger+pro+apk PDF link annotation
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/161355a7feb744---nafax.pdfIn PDF document text
    • http://riviera.az/userfiles/file/sagulibebewi.pdfIn PDF document text
    • http://centonze-vini.com/userfiles/files/fawetipatotubosaladem.pdfIn PDF document text
    • https://yourtuscanyguide.com/wp-content/plugins/super-forms/uploads/php/files/i93n941ukp8a4ei8kc89hibnm7/63009803098.pdfIn PDF document text
    • https://history.tlshaa.org.tw/ckfinder/userfiles/files/zovokapapowefi.pdfIn PDF document text
    • http://shepardinteriordesign.com/rw/upload/file/19395795904.pdfIn PDF document text
    • http://zxpgw.com/userfiles/file/70251260354.pdfIn PDF document text
    • http://www.sictombbi.fr/ckfinder/userfiles/files/97406369933.pdfIn PDF document text
    • http://pensjonatagat.pl/userfiles/file/11441496964.pdfIn PDF document text
    • https://indirimlipin.com/calisma2/files/uploads/48782779293.pdfIn PDF document text
    • http://forma8.kz/ckfinder/userfiles/files/87614375645.pdfIn PDF document text
    • http://greenglobepms.com/uploads/xetirotaw.pdfIn PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613604b9be766---67387660611.pdfIn PDF document text
    • http://lotusburbank.com/uploads/files/34516154866.pdfIn PDF document text
    • https://prcomponents.com/ckfinder/userfiles/files/neridifewegefe.pdfIn PDF document text
    • http://herfon-machinery.com/images/ckfinder/files/20210924075540.pdfIn PDF document text
    • https://growlocals.com/wp-content/plugins/super-forms/uploads/php/files/951e31d3759be4646edd9ced1d8acb7f/putaxekuf.pdfIn PDF document text
    • http://kaies.net/upfiles/file/felivatofaguje.pdfIn PDF document text
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/8cc64cbbadd2254602f719a4646e203a/21636401466.pdfIn PDF document text
    • http://bbfederico2.net/userfiles/file/47395748230.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/85237727588.pdfIn PDF document text
    • http://artpolinakuzina.ru/pict/file/64303252699.pdfIn PDF document text
    • http://sadiqandsons.com/userfiles/files/30937449180.pdfIn PDF document text
    • http://boras-sjuharad.boj.se/uploads/userfiles/files/nivimatidupekonugut.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_off0000ba25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBA25 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d23c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD23C 10412 bytes
SHA-256: eae46c035f371742b0d27ddf43803b1c45dcf9de09a90eb8db3b51ba67c8041e
font_02_sfnt_off0000e9b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9B1 19280 bytes
SHA-256: 1fd5cfd7ee52dcdc0bbf98d2e3ed9d7d00467790b5cdbb4531e760c53ca7e3e5