Malicious PDF — malware analysis report

Static analysis result for SHA-256 73c7ad421cdd95aa…

MALICIOUS

PDF

90.1 KB Created: 2021-07-01 00:59:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 41e7ead046c90d8400e11a61b45db361 SHA-1: b0f4fe31d8375a56ea2ca735aa6787931cdbf972 SHA-256: 73c7ad421cdd95aae3ad9c624920cfdc2786cd0de61408593aab165532066846
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites and disposable domains, suggesting a phishing or malware distribution scheme. The PDF structure and the nature of the URLs strongly indicate its use as a lure to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f1d1a6adcd---71020772947.pdf
    • https://hmanagement.net/userfiles/file/15212982795.pdf
    • https://parklanehotel.asia/userfiles/file/kazidafufalutuguxidotibe.pdf
    • http://wib24-admin.de/uploads/file/bapufowajibadujekapapi.pdf
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/160b01caf14f12---49310190797.pdf
    • http://akcjonariusz.com/UserFiles/file/vubisogoj.pdf
    • https://canionglobal.com/FCKeditor/file/jogutuk.pdf
    • http://xn--kprq5pvqklteonubj6c.tw/CKEdit/upload/files/saruzodegosorata.pdf
    • https://cplastik.cz/data/cms/file/81430445418.pdf
    • http://kleinschaden.expert/userfiles/file/vazunu.pdf
    • https://www.dyna-tech.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609cda3b031e8---kebaduzigiserusidibipud.pdf
    • https://vuaship.com/wp-content/plugins/super-forms/uploads/php/files/l2ptcf8d5qbai0kilu5r92lsr9/73192116446.pdf
    • http://herodumpsterrental.com/wp-content/plugins/super-forms/uploads/php/files/5af493e170404362def452ee62746215/kawinilonelebawutatala.pdf
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16070b202ada5d---xuzifefuradasiwowulosoru.pdf
    • http://www.microsinusectomi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077c9e9ec2cb---14957802870.pdf
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/90a32a44783cd555fa3001649152850f/87658716787.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1d546b1ae6---jimosizuvubusofiwuv.pdf
    • https://itacademyindia.com/ckfinder/userfiles/files/72120654897.pdf
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/160a2f21499610---judusotomeselej.pdf
    • https://bahia-group.com/ckfinder/userfiles/files/jivojuvetaxalumoxu.pdf
    • https://homini.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1608cd238ba783---69228708282.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160acad48e948b---putesetezesofisom.pdf
    • http://www.gabrielamaciel.net/images/content/file/dixaxumopixuk.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=command+to+check+tensorflow+version
    • 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_off0000f762.bin
8fcb2b1ad3e0b378e9f45b20b778e334c8948d473ad093d834c1dab6e1aa2bf5
pdf-font-stream PDF embedded font (sfnt) at offset 0xF762 18244 bytes
font_01_sfnt_off00012807.bin
314ff5f0db10721a9e7adf2903b636d65e995a9d36fb56308685eda06fe01d82
pdf-font-stream PDF embedded font (sfnt) at offset 0x12807 11016 bytes
font_02_sfnt_off00014182.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x14182 16792 bytes