Malicious PDF — malware analysis report

Static analysis result for SHA-256 31d62fd1ab64345a…

MALICIOUS

PDF

72.4 KB Created: 2021-09-08 10:46:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: e7afef839c8ab3344853808626878b74 SHA-1: 83b2205d7c10f1611bad2f9eacc659cb91b8458d SHA-256: 31d62fd1ab64345ab16077f20e2d34c91f4c8d65628cc0ee276c7bb31da57b1f
164 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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 http://mfcwestenkwartier.nl/beta/userfiles/file/surulufigilok.pdf In PDF document text
    • https://wodepcb.cn/uploadfiles/files/rabixupunonesit.pdfIn PDF document text
    • http://mingzhicc.com/userfiles/files/vagomakomu.pdfIn PDF document text
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/95ac775f7a5b396698400dfecb8e3285/vikusonoxor.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607ef6fa971d0---37267565214.pdfIn PDF document text
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c284fc5234---mexiwegoxato.pdfIn PDF document text
    • https://contabil-fiscal.ro/mm/file/bexogumemikewesivedamug.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610d6356cafd4---nebijavesetis.pdfIn PDF document text
    • http://willbramephotography.com/68569614446.pdfIn PDF document text
    • http://rockpapersun.com/upload_mce_image/file/38067815434.pdfIn PDF document text
    • https://almondzwealth.com/administrator/imagetemp/file/tolivokaxebub.pdfIn PDF document text
    • http://residenzaeden-albisola.com/userfiles/files/68063742788.pdfIn PDF document text
    • https://legacydockandmarine.com/wp-content/plugins/super-forms/uploads/php/files/26515c0e82ab0bb704c1311f1ed83655/jezanu.pdfIn PDF document text
    • http://pro-group.ru/userfiles/files/46390705765.pdfIn PDF document text
    • https://rivaflo-south.in/userfiles/files/rirufifebozetovelijixum.pdfIn PDF document text
    • http://ovartec.com/wp-content/plugins/formcraft/file-upload/server/content/files/160af9bcbbe1a9---12921145195.pdfIn PDF document text
    • http://www.hausbaumesse.at/ckfinder/userfiles/files/90030398078.pdfIn PDF document text
    • http://www.orhancoskun.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d5e30c313b---xogemoja.pdfIn PDF document text
    • http://speckrepeg.by/UserFiles/files/lamititanipaxexugesa.pdfIn PDF document text
    • https://quangcaonoithatgiahung.com/admin/webroot/upload/image/files/setegipuwigabelerik.pdfIn PDF document text
    • http://www.binghan.my/userfiles/file/80810418457.pdfIn PDF document text
    • https://medok18.ru/wp-content/plugins/super-forms/uploads/php/files/a5acf01b8a57ca3c569dd176b0288ef2/66663401546.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=addition+and+subtraction+of+fraction+worksheet+docPDF 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_off0000b588.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB588 17504 bytes
SHA-256: fb0cb618fefaef280ac1293e09853f10c318a2cccb54448396a1a5eea141a166
font_01_sfnt_off0000e295.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE295 10924 bytes
SHA-256: dba51526ea3f869870716d86919185178daa4ffb81dae71e7110320c6e40d695
font_02_sfnt_off0000fbfd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBFD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1