Malicious PDF — malware analysis report

Static analysis result for SHA-256 813a1ec17338d782…

MALICIOUS

PDF

97.9 KB Created: 2021-06-24 02:48:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-04
MD5: 77cbb67468402812a4cbfedb1e6c09e9 SHA-1: aa26570e8567f85d41e2eaaf8d7d2637cbf3b72b SHA-256: 813a1ec17338d78213d4562e60b6123e37341f9ecbe3ddf1ebb2dcd6f1100601
164 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript 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 and contains embedded JavaScript. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://wastran.ru/uplcv?utm_term=cambridge+ielts+9+reading+test+1 PDF link annotation
    • https://centrorevisionimonregalese.it/file/besora.pdfIn PDF document text
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094a78ea8729---goginabuduzesewur.pdfIn PDF document text
    • http://ohsclassof73.com/clients/9/9a/9a21b0b253f7c4eafe662346d237c286/File/33392393026.pdfIn PDF document text
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/88b1974a1ca9473bcfba644e21cfbaea/kikujepiwulowenarixefo.pdfIn PDF document text
    • https://feriaesotericadeatocha.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093fd02419ec---49950932756.pdfIn PDF document text
    • https://reitinguok.lt/userfiles/file/48406188499.pdfIn PDF document text
    • http://garageanything.com/js/upload/files/24935215661.pdfIn PDF document text
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/160bbc93c4a09c---ziwakinabuxipik.pdfIn PDF document text
    • https://hopefor.today/wp-content/plugins/super-forms/uploads/php/files/9d4f8ec7d5627d61c1a4e6484629aade/sajabojiv.pdfIn PDF document text
    • https://cor.org.ar/wp-content/plugins/super-forms/uploads/php/files/lthinseb4lho3ihm8gj561t84v/pupib.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/682979268db4e3b66e56811b43b2324c/novivixekiperupizifetima.pdfIn PDF document text
    • http://maychamsocda.vn/images/userfiles/file/kozadolatatuda.pdfIn PDF document text
    • https://cashmeredreams.com/wp-content/plugins/super-forms/uploads/php/files/476d4b7ba4e85c2a4962ff1f93364729/91423380266.pdfIn PDF document text
    • https://buka.ru/sadm_files/1928659370.pdfIn PDF document text
    • https://wentworthre.com/wp-content/plugins/super-forms/uploads/php/files/f998f223bb2b104f4ed820a83d051ce9/jotulusi.pdfIn PDF document text
    • http://dralituncer.net/userfiles/file/jotefusifibel.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn 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_off00011d47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D47 5396 bytes
SHA-256: c12ebb63d32f8ca7815b141e06cca3242d27f9b3e79ffe327582e95733b5c9ce
font_01_sfnt_off00012f7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F7D 23068 bytes
SHA-256: 2fa30fe8dd4f6842e26367b783f593bce44737b4b4099970ee3377be6221f146
font_02_sfnt_off00016396.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16396 16068 bytes
SHA-256: 5338b60dac2ddcc9fbf81734882903060897ff8c18563aad6864a581beec55c6