Malicious PDF — malware analysis report

Static analysis result for SHA-256 1a3c101ec70a0e99…

MALICIOUS

PDF

81.4 KB Created: 2021-09-21 20:33:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: 5d7c91bedb33b4b7dd6980d1fc046d74 SHA-1: d351db54e4a5975e36850d2c39216d4034c011e4 SHA-256: 1a3c101ec70a0e996d1ae88ab79673a16c06714f4bf31006a1d44345f06a4905
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://drafthe.ru/uplcv?utm_term=tts+reader+mod+apk PDF link annotation
    • http://www.anclupnapoli.it/userfiles/file/63188197730.pdfIn PDF document text
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/16134c37b2985e---49609317944.pdfIn PDF document text
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f642117126---sabupaduma.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/5d6cd63722ae85abbd28bc7a584d64a0/42705189170.pdfIn PDF document text
    • https://coastalstudio.com/images/main/file/reganura.pdfIn PDF document text
    • http://xn--h49al33a2zdp0eo1x.com/DATA/file/20210913035334.pdfIn PDF document text
    • http://shinserviceodi.ru/wp-content/plugins/super-forms/uploads/php/files/079226271a09df978382632bd4846c1e/januw.pdfIn PDF document text
    • https://californiaoptionsrealestate.com/wp-content/plugins/super-forms/uploads/php/files/6c2f30cd837ce4a06e633027f4a91345/81013868004.pdfIn PDF document text
    • http://ceramvetro.net/userfiles/file/98695822327.pdfIn PDF document text
    • http://studiozoppini.com/userfiles/files/40435153046.pdfIn PDF document text
    • https://serka.com/serka/upload/files/67060406502.pdfIn PDF document text
    • http://headrepublic.pl/images/files/93623136717.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141f1d06d850---nitunilenexemaxubeti.pdfIn PDF document text
    • http://kozhencherrymtc.org/userfiles/file/69911142462.pdfIn PDF document text
    • http://camel-republic.com/media/userfiles/files/45132174.pdfIn PDF document text
    • https://invision.buzyhub.com/files/54237006951.pdfIn PDF document text
    • http://kaupa.cz/userfiles/file/fafevurixuwefipepizu.pdfIn PDF document text
    • http://35ju.21tg.cn/uploadfile/ckeditor/files/76076006750.pdfIn PDF document text
    • http://mayinluatudong.com/uploads/userfiles/file/44239583233.pdfIn PDF document text
    • https://muacash.com/webroot/img/files/fatojonodapomov.pdfIn PDF document text
    • http://cs-golfclub.com/ckupload/files/bivesifibigezapuzelulova.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_off0000d7a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7A8 18544 bytes
SHA-256: 8d4d725ef9eaccb337814512afcab646d652472ac6ac46eea16baa2c828bb829
font_01_sfnt_off00010866.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10866 10364 bytes
SHA-256: 65b8dd6e111ceed52da41f9e9960e7b963aea2285421f84d87f536c60e04278f
font_02_sfnt_off00011fe6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FE6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1