Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8a341b3f7db6c9e…

MALICIOUS

PDF

85.3 KB Created: 2021-07-03 19:59:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 041bf4eea4b96fec27aa9780d9c58327 SHA-1: ad54ad95c342682e2ad50827d1a42f92e8a12b2c SHA-256: c8a341b3f7db6c9e3245397943a427d467de95e63cdd3ddf4aca775df07a113b
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous URLs that point to compromised CMS uploads and disposable hosting, suggesting a phishing or malware distribution scheme. The presence of multiple external URIs and the overall structure strongly suggest this document is intended to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://ketchas.ru/uplcv?utm_term=glandered+horse+meaning
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608cf9b5d2101---74704957239.pdf
    • https://vildmarksjagt.dk/userfiles/file/sinebajareguvidolaw.pdf
    • http://asja-doll.ru/userfiles/file/8805472530.pdf
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/f242c8f5b2bf2dbd3d019e847a0207e2/65087247387.pdf
    • https://www.blackandwhite-salon.com/wp-content/plugins/super-forms/uploads/php/files/4c02f57be940de0fcb75aa333915e5bc/nexaderuwojojetowi.pdf
    • http://voxel-avocats.fr/uploads/file/besovipixetebisuxa.pdf
    • http://airconbank.com/upload/fckeditor/file/sowadanuna.pdf
    • https://arizonalightingsales.com/wp-content/plugins/super-forms/uploads/php/files/5f841f1daec4fc93175fa2ef2f9c8aed/davatiwulete.pdf
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1292d8133b---xewak.pdf
    • http://auto4-spb.ru/public/images/ckfinder/files/fopanixirabakuwisifa.pdf
    • http://kamerton.nl/clientfiles/ziriwazo.pdf
    • http://www.socalgreatwhite.com/wp-content/plugins/formcraft/file-upload/server/content/files/160764a7fdb759---5382848342.pdf
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/1608133e65b85e---68809528149.pdf
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160bd65f2e3535---mitixowokipok.pdf
    • http://safires.cz/ckfinder/userfiles/files/vomasisu.pdf
    • https://thefertilizerequipment.com/d/files/35553398527.pdf
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b843511afa8---17971204994.pdf
    • http://ckrestaurantgroup.com/ckfinder/userfiles/files/vogomalolorilesabud.pdf
    • http://rc-modeller.se/images/file///nokogafaguvunolaboz.pdf
    • https://bhsbeacon.com/FCKeditor/file/85047522580.pdf
    • https://www.beachesbrewing.com/wp-content/plugins/super-forms/uploads/php/files/af146f70b0916fb49fcb9f5d88ae2c8f/58383919158.pdf
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609fdaf1888bb---pupudop.pdf
    • https://centrobrands.com/wp-content/plugins/super-forms/uploads/php/files/df4569326c75d542f4fd4c7df213df89/tuwumisunukajasux.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_off0000eb03.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEB03 16792 bytes
font_01_sfnt_off0001031a.bin
08598747c81366e384a7a731742d26619963e23b387ec74e4d96b4745e0f3ac0
pdf-font-stream PDF embedded font (sfnt) at offset 0x1031A 10636 bytes
font_02_sfnt_off00011af6.bin
53ef9d77bd7d7d2c09d8b39ca44f4e788be013b60e5f924d38633fa31f9a3c7d
pdf-font-stream PDF embedded font (sfnt) at offset 0x11AF6 17364 bytes