Malicious PDF — malware analysis report

Static analysis result for SHA-256 f23b456adf6a3068…

MALICIOUS

PDF

85.3 KB Created: 2021-09-17 09:23:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: aea25a46fb8dffc2aa4f12ee6bb4a4b3 SHA-1: 339bd404f7a6815ff8910418e310d908df650bc2 SHA-256: f23b456adf6a306821ce2d29c6220e1c2cec251ca05ecbbab94200978b6e3a80
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://springkasteelhuren.be/userfiles/file/67970543292.pdf
    • http://www.lukoilmarine.com/ckfinder/userfiles/files/sorilufube.pdf
    • https://askisan.com/upload/ckfinder/files/ralulotiviki.pdf
    • https://pvcmikser.com/upload/files/netozatil.pdf
    • http://kd-council.com/upfile/files/28676301336.pdf
    • http://good163.cn/Uploadfiles/files/38781413928.pdf
    • http://airconbank.com/upload/fckeditor/file/22056881860.pdf
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16139f8e6f3eba---mexorapizevim.pdf
    • http://dreiseengrundschule.de/files/6428621494.pdf
    • https://fsbulletsandbrass.com/userfiles/files/52816604593.pdf
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161316aa15e839---banijujezeditotex.pdf
    • http://bbdecontra.com/userfiles/files/54840816825.pdf
    • http://rideabikenews.com/user_img/files/poturege.pdf
    • http://saatgaamkansarasamaj.com/admin/uploads/files/58421404654.pdf
    • http://max-metal.pl/gfx/file/40001158037.pdf
    • http://nirmalamathachurch.org/cms_uploads/image/file/tabapigubozolu.pdf
    • https://badrivishal.com/media/zevigulalokulikulewu.pdf
    • https://mobspace.xyz/web/img/podborky/files/39617314414.pdf
    • http://holzweiss.at/56615048805.pdf
    • https://satnamunicipalcorporation.com/admin/ckfinder/userfiles/files/20752300615.pdf
    • http://moriefrusca.com/userfiles/files/98627546622.pdf
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d5667ef003---bajobimabunojamul.pdf
    • https://majubesar.net/contents/files/fiwanoboxogojupujawezev.pdf
    • http://portalcom-b2b.es/img/user//file/_0275881001631284114.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=popcorn+time+firetv
    • 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_off0000e361.bin
b223a79180c6ae8eb9e1778939c78fd86cd3ce23cda3dc4f1307a37220547ff1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE361 20836 bytes
font_01_sfnt_off000118c9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x118C9 16792 bytes
font_02_sfnt_off000130e0.bin
3ecd90f0a948af7fc1f5ce426e3a9a62ecf9af59ae1ed5a7d2b9f68b709ef6b3
pdf-font-stream PDF embedded font (sfnt) at offset 0x130E0 10332 bytes