Malicious PDF — malware analysis report

Static analysis result for SHA-256 316b55bef0e2a62d…

MALICIOUS

PDF

89.1 KB Created: 2021-09-18 14:10:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: d2c6e8319bfddb96faab9bfb8fedd7f1 SHA-1: 5f7837e0c25a948914dcf8a73263944f2fc50f38 SHA-256: 316b55bef0e2a62d4cc9bce9ffb0a772908cc2b2d27a5423fce50d4bbb7ab276
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 websites or disposable hosting, forming a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery through these links. The presence of link farm heuristics suggests an attempt to obscure the final destination and evade detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

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 http://zhjpharm.com/upload/files/wonup.pdf In PDF document text
    • http://fu-xin.tw/uploads/files/202109090053285115.pdfIn PDF document text
    • http://oaklandscreche.ie/userfiles/files/xutodaz.pdfIn PDF document text
    • http://goldmustang.com/files/files/46970162597.pdfIn PDF document text
    • http://hamzalegalservices.com/userfiles/file/vorezitedawamof.pdfIn PDF document text
    • https://history.tlshaa.org.tw/ckfinder/userfiles/files/55553659068.pdfIn PDF document text
    • http://klm-co.ru/foto/ck/files/nutupopovel.pdfIn PDF document text
    • https://highlander-inn.com/assets/userfiles/files/51270363734.pdfIn PDF document text
    • http://izhar-energy.com/userfiles/file/kugokikavebefeguseza.pdfIn PDF document text
    • http://canadianartistic.com/userfiles/file/rozoparavefolisigasimapir.pdfIn PDF document text
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ec12d6cf67---tidakelawasixamaguvurawof.pdfIn PDF document text
    • https://kemxoithanhhang.vn/app/webroot/files/images/pages/files/94634776240.pdfIn PDF document text
    • http://maiodi.com/userfiles/files/nasifuzaxugekujigalixirod.pdfIn PDF document text
    • https://alpinashop.bg/files/54398520979.pdfIn PDF document text
    • https://rebates.forex/wp-content/plugins/super-forms/uploads/php/files/ftf366eo9v61d6k0oh17j39l91/gumidivu.pdfIn PDF document text
    • https://jaukiaplinka.lt/ckfinder/userfiles/files/fonanolebujitavaloxi.pdfIn PDF document text
    • http://bzws.zhanyougame.com/ckfinder/userfiles/files/11089981954.pdfIn PDF document text
    • https://fallsplat.se/bildbank/file/38327512120.pdfIn PDF document text
    • https://adesso-moosburg.de/images/file/45473803476.pdfIn PDF document text
    • http://jmyhship.com/uploadfile/files/kixugabigoredaj.pdfIn PDF document text
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613484f11cc88---pegivap.pdfIn PDF document text
    • https://candica.pl/ckfinder/userfiles/files/karonal.pdfIn PDF document text
    • http://thebookmarkcafe.com/uploads/files/47325922168.pdfIn PDF document text
    • https://drrajanmahtani.com/userfiles/files/siwerezobasuverunujel.pdfIn PDF document text
    • http://productinfo.in/konadnew/userfiles/file/xutidifuledewop.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=antutu+benchmark+moto+g9+plusPDF link annotation
    • 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_off0000f5fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5FE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010e10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E10 18096 bytes
SHA-256: 253de9bb2eb73c642cd4f9a1e195668d64fd4c70b970555aabafbad87e06df4e
font_02_sfnt_off00013d0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D0C 11212 bytes
SHA-256: 97c5ba68050d5baa0a31c4851f6385c3fb8e18f30c5b6b98ba039f4b68aa2372