Malicious PDF — malware analysis report

Static analysis result for SHA-256 a11e5b7c6af0560b…

MALICIOUS

PDF

81.8 KB Created: 2021-09-15 10:59:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2d4de39433bb9c4efbedc5041c038fce SHA-1: 3d1c38578ecb59b78979a217727967d17f4c475d SHA-256: a11e5b7c6af0560b993227820f51d491a7140041b14fdc512d3206ee3119ece8
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised websites, identified by heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM'. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is unreadable, but the presence of numerous external links suggests an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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 http://globalone-mould.com/gbw/fckfiles/20210905175739.pdf
    • https://www.renfrewareahealthvillage.ca/ckfinder/userfiles/files/41667590105.pdf
    • https://familienbilstrup.dk/userfiles/file/76835253466.pdf
    • http://zbigniewrodak.pl/galeria/file/suwerejuluparuvuzo.pdf
    • https://www.grdr.org/paidel/ckfinder/userfiles/files/72028740660.pdf
    • https://koltoztetes-szallitas-lomtalanitas.excore.hu/ckfinder/userfiles/files/62230623098.pdf
    • http://vdgairconditioning.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613109add282f---vodemibuv.pdf
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137d30778e90---jiwawebejuwamopobi.pdf
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/161387dc92861a---kulasijikefikesabamub.pdf
    • http://geologicatoscana.eu/userfiles/files/93230717881.pdf
    • http://gardena.crazyrockinsushi.com/uploads/files/lifewulirewasasojo.pdf
    • http://madmojo.com/fckupload/file/kulezaminopameralek.pdf
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/16140917d28843---44201626763.pdf
    • http://www.danvillern.com/wp-content/plugins/super-forms/uploads/php/files/d74c6e8805b9021658fe3a59878e0989/fonevojikev.pdf
    • http://nhasachthunam.com/upload/files/wixozudajujawanezag.pdf
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/16139a178709b1---11588833954.pdf
    • http://devveb.net/userfiles/file/57056196660.pdf
    • http://nm-union.ru/ckfinder/userfiles/files/nojowe.pdf
    • http://jd6618.com/jd6618/file/2021-9/file/LwpCms2021_09_11_13_23_06_8127.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=android+system+service
    • 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_off0000db73.bin
992485d3195096bb955090f27caa3fa7f506ea9e63ec3c73c1fafef069352171
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB73 17732 bytes
font_01_sfnt_off000109e2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x109E2 16792 bytes
font_02_sfnt_off000121f9.bin
64c408e1d4d0f97671c0160b5d7f237dd8f61e4da4c8cea835202ee0e5b400f5
pdf-font-stream PDF embedded font (sfnt) at offset 0x121F9 10484 bytes