Malicious PDF — malware analysis report

Static analysis result for SHA-256 5d5368fbae51f679…

MALICIOUS

PDF

85.9 KB Created: 2021-06-20 13:54:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-27
MD5: a9b31784ea03ea6771329763873150b3 SHA-1: d8c41f4f9e479d412ee487ae746dc26b94330786 SHA-256: 5d5368fbae51f679a90e862353e25b9bf0c62943291974ff7e43c0e02da7dc2d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a link farm pointing to multiple compromised websites, suggesting an attempt to distribute malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a phishing lure, potentially using embedded JavaScript to facilitate the download of a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/79b0c00b824a1d7b521dc91b757048ac/96240475534.pdf In PDF document text
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e67c73318c---62595647569.pdfIn PDF document text
    • https://imagebeaute.fr/userfiles/file/44014472535.pdfIn PDF document text
    • https://primer-spb.ru/files/files/95555357921.pdfIn PDF document text
    • https://ludifrance.fr/userfiles/file/ruraxerigigofevofozowixam.pdfIn PDF document text
    • https://expresstestingatl.com/wp-content/plugins/super-forms/uploads/php/files/d7193490986f4880f581da987bfcf6c5/69607007569.pdfIn PDF document text
    • http://xn--e1aazeoc7d.xn--p1ai/images/shared/file/baxunolefubopoki.pdfIn PDF document text
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/f9b23886fe0cf0be491cb68082f682b9/15759199536.pdfIn PDF document text
    • https://www.ptlittleflower.org/wp-content/plugins/super-forms/uploads/php/files/1759cibn1uqiqo7j8es951o0dn/nuxinifejofixu.pdfIn PDF document text
    • http://romanakladatelstvi.cz/userfiles/file/54163152274.pdfIn PDF document text
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/879a63c29bd2155c614ecd3b517cde22/11514436779.pdfIn PDF document text
    • https://thejasmineway.net/wp-content/plugins/super-forms/uploads/php/files/99hctgck2iqm3s6jm4ap24b97r/57396036851.pdfIn PDF document text
    • http://www.johnknox.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1609ba16448795---timeminoveri.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.opentle.orgIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=download+physics+textbook+for+secondary+schoolPDF 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://scripts.sil.org/OFLIn PDF document text
    • http://www.gnu.org/licenses/gpl.htmlIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e19a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE19A 5496 bytes
SHA-256: 19ee344775d7916768a5b6e3cac31dc4f75f17d1df12325db2f52af2c003cf9c
font_01_sfnt_off0000f44e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF44E 5852 bytes
SHA-256: 4898a065fb0c16b974e9a02d7df6b2166b133689e51422f07b6cdada0fbdb129
font_02_sfnt_off00010307.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10307 11064 bytes
SHA-256: 1e50829366e6079eb2cf03ddb096bb4e5070e47c1ebd10a67ee86100b1def082
font_03_sfnt_off000128de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128DE 16028 bytes
SHA-256: 6e14d9a23925fbdd927c7db5f893cbd4d80a19524b1aae448d44ee15d2611241
font_04_sfnt_off00013d26.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D26 4324 bytes
SHA-256: b50a2106bf82917db0cd3cf88f63c5e8cc3298b343ace5cffc591b35df33d24c