Malicious PDF — malware analysis report

Static analysis result for SHA-256 b15c1ab2a6a82bf5…

MALICIOUS

PDF

85.5 KB Created: 2021-09-19 01:08:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 0b82ba3d2ca594014d8f06a1e699eee7 SHA-1: 7313cdc61004e2baa2ecacc0da284e987607e80d SHA-256: b15c1ab2a6a82bf56989d5cd5cc8929244c077f3e362dcaf538c435050ba520a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs pointing to various domains, many of which appear to be compromised or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly indicate this document's purpose is to act as a link farm. The ML classifier and ClamAV detection confirm its malicious nature, likely serving as a lure for phishing or to distribute further malware. No scripts were extracted, but the embedded URLs are the primary indicators of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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://smidgel.ru/uplcv?utm_term=zombie+stick+war PDF link annotation
    • http://www.xzass.org/ckfinder/userfiles/files/lizotezedetunepebiba.pdfIn PDF document text
    • https://yuktiedu.com/wp-content/plugins/super-forms/uploads/php/files/8b43f35835ca79b26c052c4d1d1d9795/57868176180.pdfIn PDF document text
    • http://pescepiana.eu/userfiles/files/47552176360.pdfIn PDF document text
    • http://ozkayalarlojistik.com/userfiles/file/8025322925.pdfIn PDF document text
    • http://globalfeedindustry.com/upload/files/31224048631.pdfIn PDF document text
    • http://omniatel.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613597a4853ec---tebizezunifete.pdfIn PDF document text
    • http://noclegsosnowiec.pl/eurostyl/photos/file/lotafige.pdfIn PDF document text
    • https://comptables-publics.fr/userfiles/file/xosifevezibokagupazenur.pdfIn PDF document text
    • http://minhledtran.com/luutru/files/56557742063.pdfIn PDF document text
    • http://lucchetta.net/userfiles/files/xesototew.pdfIn PDF document text
    • http://ornito-silesia.eu/userfiles/file/xemufatapixogusubepaxeg.pdfIn PDF document text
    • http://star-transform-moscow.ru/uimg/files/nimowowo.pdfIn PDF document text
    • http://snap-drone.com/userfiles/file/37049529636.pdfIn PDF document text
    • https://detector-billetes.com/Imagenes/file/38505643904.pdfIn PDF document text
    • https://www.higher-energy-trampolineclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/161425b9a4f6a7---2415952630.pdfIn PDF document text
    • http://badgerhillfarm.uk/pukoliwawowixamenenivil.pdfIn PDF document text
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/28c887b04744c7922cd3df7ae31a444f/bunajokiw.pdfIn PDF document text
    • https://www.indoorclub-informa.com/boletines/img/file/50018317765.pdfIn PDF document text
    • http://cioccolatogallucci.it/userfiles/file/bawotuvubarul.pdfIn PDF document text
    • https://www.nvsrolko.org/ckfinder/userfiles/files/dujodiz.pdfIn PDF document text
    • http://ks4073.com/file_media/file_image/file/lozasapideri.pdfIn 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

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e9ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9AD 10520 bytes
SHA-256: 4b9b581e6d61726f975518b68735f0f606f07304a47f73ae210fa1bf1da5b2d1
font_01_sfnt_off000101cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101CC 18068 bytes
SHA-256: d622e806db9c44a5d18943ae040addfa55289b29427361ed3ef124f3862f65b3
font_02_sfnt_off0001312f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1312F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1