Malicious PDF — malware analysis report

Static analysis result for SHA-256 35157bf0b444383b…

MALICIOUS

PDF

112.9 KB Created: 2021-06-11 15:50:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-02
MD5: d4fdc87e70ac49382bb7cf658614243a SHA-1: e3b5196b02d6d4f40bfa7d05764657a39f8d73a7 SHA-256: 35157bf0b444383b9f2b079f762d20f018d9047dfe75270eb1ccaa9f9577f5fe
156 Risk Score

Malware Insights

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

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. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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.
  • 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=ayatoul+koursiyou+en+fran%25C3%25A7ais+pdf PDF link annotation
    • https://maxim-catering.de/wp-content/plugins/super-forms/uploads/php/files/c9hhov5djfl180sprrenma1mtu/molorepi.pdfIn PDF document text
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160aa7de71dad5---disobanamipokenipige.pdfIn PDF document text
    • https://gruntbudowa.pl/files/file/jizezevuvubuwojebiwezili.pdfIn PDF document text
    • https://jetzterstrecht.hamburg/wp-content/plugins/super-forms/uploads/php/files/0u4slqmhl8p43daa3i95r9qbhe/40702397139.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160c2dc594195c---83398594340.pdfIn PDF document text
    • https://www.ideakliniksisli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d42de533a8---mavurupivusawinurati.pdfIn PDF document text
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/obkbfun9m58l3aas8c9pqvo36c/95614323281.pdfIn PDF document text
    • http://www.rebranded.tv/wp-content/plugins/formcraft/file-upload/server/content/files/160b4c94b85bcd---17542722274.pdfIn PDF document text
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2ff4e34f5f---21948198438.pdfIn PDF document text
    • http://reicar.dk/userfiles/file/pigipijidisir.pdfIn PDF document text
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/tavdje2c8932m5d1jss8e8iial/56918120865.pdfIn PDF document text
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/6279a7086aa18062ed690e2e9c8a6880/6362817462.pdfIn PDF document text
    • http://www.xpresswedding.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac81b044a81---sezomuzunuwoduroresapu.pdfIn PDF document text
    • http://1hozain.ru/files/userfiles/files/64285066939.pdfIn PDF document text
    • http://bjallstar.com/upload/file/55733525425.pdfIn PDF document text
    • http://usaoxin.com/userfiles/2021-5/file/21099797043.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off00018963.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x18963 24384 bytes
SHA-256: b2b44276f99e07d2903ab704ca78f2e4bfcea707147cedff24201716945eb35d
font_00_sfnt_off00014900.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14900 5372 bytes
SHA-256: ac7cb2e3ffcab44ff65be3f670d9f2201469361c2711cacb3bd194c1561a2a23
font_01_sfnt_off00015b65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15B65 15236 bytes
SHA-256: c822bd2e8ca18855b778e7afb0cadd488e4aeccf0a10136f3858e3f7891080be