Malicious PDF — malware analysis report

Static analysis result for SHA-256 9781d84f8526d460…

MALICIOUS

PDF

75.7 KB Created: 2021-09-22 19:54:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 0f11ae64130af679edc97b919f7e3815 SHA-1: 24375090a5170c85f0adb99bfc9d8e68fda5ab26 SHA-256: 9781d84f8526d4608c66e1c42c5d6e68dea209609d4317b5943740e1df570048
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains embedded JavaScript and a link farm pointing to multiple domains, some of which are hosted on compromised CMS uploads. The primary purpose appears to be redirecting users through these links, likely to phishing sites or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://cructi.ru/uplcv?utm_term=over+the+hills+led+zeppelin+tab PDF link annotation
    • http://ricarda-allegra.de/userfiles/file/99400502065.pdfIn PDF document text
    • http://bangladeshceramicsociety.com/uploads/editor/files/85405344836.pdfIn PDF document text
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16131943202dbd---jopazopuxagiri.pdfIn PDF document text
    • https://fetogram.ir/images/upload/files/81380436480.pdfIn PDF document text
    • http://webmba.fr/client/logo/file/vinasunozijuzakuk.pdfIn PDF document text
    • http://eyela.kr/uploadfile/fckeditor/file/76481765454.pdfIn PDF document text
    • http://aci-immobilier-douai.fr/userfiles/files/43323740178.pdfIn PDF document text
    • http://www.jacenter.org/js/ckfinder/userfiles/files/45958118926.pdfIn PDF document text
    • http://angarakshaksecurity.com/userfiles/file/nixaretazexomuwifo.pdfIn PDF document text
    • http://www.dfdtrading.sk/ckfinder/userfiles/files/fepolakimirepabovofelojo.pdfIn PDF document text
    • http://ctkupavna.ru/upload/file/ridagixudipereluzurinona.pdfIn PDF document text
    • http://tapestry.cz/images/file/files/42668993004.pdfIn PDF document text
    • http://codemessaging.net/ckfinder/userfiles/files/39181629988.pdfIn PDF document text
    • http://www.nachtruhe.info/up/files/denivute.pdfIn PDF document text
    • https://www.aifimm.it/admin/inc/ckfinder/userfiles/files/rexiziposopexiteborakeret.pdfIn PDF document text
    • http://monkey-do.net/userfiles/file/55733050494.pdfIn PDF document text
    • http://studioagronomoserragiotto.eu/userfiles/files/73956494812.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/tbrr865jos7shmsrufl5ia85f9/vovuxemaladizepura.pdfIn PDF document text
    • http://ksnjl.com/userfiles/files/kajutifomumanus.pdfIn PDF document text
    • http://andreevmag.com/wp-content/plugins/super-forms/uploads/php/files/a2e70c81223cf2a304acab08c43fb295/51579561937.pdfIn PDF document text
    • http://duet-czluchow.pl/userfiles/file/waxepujevazojurobuwa.pdfIn PDF document text
    • http://zamaro.cz/images/fcke_files/file/4369732025.pdfIn PDF document text
    • http://dintainoodle.com/uploads/files/21146200501.pdfIn PDF document text
    • http://penzionnakrizankach.cz/ckfinder/userfiles/files/33001317264.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_off0000c22b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC22B 17692 bytes
SHA-256: 7084a0d5f08eae947b1d7dd6b38a81d0fb0920ec59aba169bfe0fc4299930eab
font_01_sfnt_off0000f07f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF07F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010896.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10896 10660 bytes
SHA-256: c06888ed9bee685a365768a10cd24b5510cfdd5332d76abf276cfb97608906f8