Malicious PDF — malware analysis report

Static analysis result for SHA-256 2878eea07a71b37a…

MALICIOUS

PDF

75.3 KB Created: 2021-09-11 11:46:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5f3ce5c8e9370d7a310ac95d0932f961 SHA-1: 632f2e605757d1d4e73fe61b9dd3b3092e3f7bf0 SHA-256: 2878eea07a71b37ab81dabe0886d68ea478e8b508be2cf865fa13155bee7c28e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS platforms. The presence of PDF_SEO_DISPOSABLE_LINK_FARM suggests an attempt to leverage search engine optimization for malicious redirection. No scripts were extracted, but the PDF structure itself facilitates the redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://medvor.ru/uplcv?utm_term=motorola+one+5g+root
    • https://yomadesign.com/userfiles/Proj_Name/files/filunododazilufapovokul.pdf
    • https://ckeditor.pamlskovnik.cz/ckfinder/userfiles/files/zipuwoxujemogufixawavafep.pdf
    • http://phongkhamthienhoa.vn/images/files/25139393596.pdf
    • https://mamo-tato.ro/userfiles/file/mifolakurebumujevifuxe.pdf
    • https://fundacjanadzieja.com/images/wyswig_images/file/buvezekisejexuz.pdf
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16130cb9494fd6---fepuxogomizogeworoxewuwi.pdf
    • http://njuhome.pl/ckfinder/userfiles/files/7355660317.pdf
    • http://ulv-fogger.ru/d/files/kazaxajazepiguf.pdf
    • http://mjengo.org/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/76122399703.pdf
    • http://fruitsad.pl/images/file/2726017820.pdf
    • http://cnex.cc/images/blog/file/42890055313.pdf
    • https://soosekszer.hu/upload/files/57581369197.pdf
    • http://nuitsdartistes.eu/images/file/61630542871.pdf
    • http://888spirits.com/userfiles/file/86484416021.pdf
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613900532833c---99508778696.pdf
    • http://refinerlink.com/userfiles/file/98567253583.pdf
    • https://ibshospitals.com/userfiles/file/78003441100.pdf
    • http://irths.com/upload_files/files/sevol.pdf
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131022ccedfe---wokadikafubi.pdf
    • http://jenan.com/ckfinder/userfiles/files/53607963313.pdf
    • https://southernwashpros.com/nbloom/fckuploads/file/80246118400.pdf
    • https://stpatswatertown.org/ckfinder/userfiles/files/fiwilo.pdf
    • http://lexprikson.com/admin/style/images/userfiles/file/48955053852.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c3cc.bin
4dc9ba13fcbfa95f9ee55a3ec3d5d0fe670cd47097863d48deb9a7ebf284324f
pdf-font-stream PDF embedded font (sfnt) at offset 0xC3CC 17400 bytes
font_01_sfnt_off0000f0d0.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF0D0 16792 bytes
font_02_sfnt_off000108e7.bin
ad55aff47b39fe1e21d25948ce8b0760a6297f915a7c90e91e349f6e59ee470d
pdf-font-stream PDF embedded font (sfnt) at offset 0x108E7 10152 bytes