Malicious PDF — malware analysis report

Static analysis result for SHA-256 8881d6d284cb4e13…

MALICIOUS

PDF

80.6 KB Created: 2021-09-13 15:10:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 05ffac3e192d01abb7ecaab0c987abe8 SHA-1: 0addf5f795dbb882c82d20ed81080b299f221eeb SHA-256: 8881d6d284cb4e13305b105a9d755df04acbe4a286a581a5259f0f8c63b7747b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, suggesting a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. Although no scripts were directly extracted, the PDF structure and URL patterns are consistent with techniques used to deliver second-stage payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://dazhonghua1688.com/ckfinder/userfiles/files/51399619679.pdf
    • http://asustainable.com/global/file/94141416244.pdf
    • http://studiomontironi.eu/userfiles/files/folubarogom.pdf
    • https://audit-advisers.com/userfiles/file/sunefanunelu.pdf
    • https://togeltop.net/contents/files/wiwutofimisomiriduzuso.pdf
    • http://air-con.ru/upload/files/63411340416.pdf
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1612f6139629a1---tejerusajidewofu.pdf
    • http://wumag.pl/userfiles/file/52607926895.pdf
    • http://www.advokat.com/app/webroot/img/fck/file/zevixodezatugaki.pdf
    • http://prochem.vn/images/uploads/files/7107866881.pdf
    • http://dycelife.com/userfiles/file/48864993640.pdf
    • http://qapoll.com/2015/vat/upload/files/82589890932.pdf
    • https://xn--fiqa735be48e.com/upload/files/bimivexexatogal.pdf
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613a6b1725a34---basutava.pdf
    • https://maggievanostrand.com/uploads/media/file/zivop.pdf
    • http://matraholding.hu/images/userfiles/files/wavibotevixegijon.pdf
    • http://kmjmt.com/news/upload/file/2109071949595782473vwzt7.pdf
    • http://gldbirdgel.com/user_img/files/vazozabeda.pdf
    • http://www.gieskestukadoors.nl/ckfinder/files/files/tupidorilu.pdf
    • https://dalton-english.com/userfiles/file/64521668806.pdf
    • http://szpk.hu/_user/file/47148479013.pdf
    • http://desiaussies.com/ckeditor/uploads/files/jagineruzufapupagozinamod.pdf
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/161383a8cd6b13---rorel.pdf
    • https://pelletier-tp.fr/ckfinder/userfiles/files/42876635249.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=pokemon+xy+game+gba+download
    • 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_off0000d681.bin
43da7fcfd3cdbea6a56dc43268943ad99dc2134dd3d167f726d7d7c2545145ae
pdf-font-stream PDF embedded font (sfnt) at offset 0xD681 10668 bytes
font_01_sfnt_off0000eec8.bin
9de03e3b2c68302c3af7c4b55dfda358deefdc56f2d0553b9740f817a735115e
pdf-font-stream PDF embedded font (sfnt) at offset 0xEEC8 17940 bytes
font_02_sfnt_off00011d2b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D2B 16792 bytes