Malicious PDF — malware analysis report

Static analysis result for SHA-256 a99844744bcd898c…

MALICIOUS

PDF

82.7 KB Created: 2021-07-05 04:43:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 61990282476841e44b963d9b4a1ed2a6 SHA-1: 3506c7fe281f65f6b9116d159f765633fece9069 SHA-256: a99844744bcd898caeecb4ead2793682e15f8f4e3a655b0acd50de80d060bdce
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous URLs pointing to potentially compromised WordPress sites and disposable hosting. The primary purpose appears to be redirecting users to external sites, which is a common tactic for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://youstore21.com/wp-content/plugins/super-forms/uploads/php/files/c4febb4a48c35b2a952b870e48bbf704/2116546293.pdf
    • http://ecbpolska.pl/wp-content/plugins/super-forms/uploads/php/files/7f11c1f1d7c92e0d90f3f68c82ae1b00/6516592235.pdf
    • https://lerong.vn/wp-content/plugins/super-forms/uploads/php/files/661545f17b76c1e21a37b2ffb69e7e7e/jutedanigokobivakug.pdf
    • https://hinodanang.com/uploads/image/files/57132013214.pdf
    • https://wills.sg/wp-content/plugins/super-forms/uploads/php/files/e0af2310221f7257a9131596b4f3fef0/59174210735.pdf
    • http://laweasy.kr/userfiles/file/siwufelel.pdf
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f28865e693---wiruremexexumajefejolusi.pdf
    • https://www.siemers-deutschmann.de/wp-content/plugins/super-forms/uploads/php/files/jkppo3bu3r3ts8uqcc99jgi993/22477888192.pdf
    • http://taskentcompany.com/userfiles/file/92655816931.pdf
    • http://centrons.com/uploaded/file/93547191560b7e5e6c0027.pdf
    • http://perlawarmii.pl/userfiles/file/pirokituwamonu.pdf
    • https://rosedreamholidayhomes.com/ckfinder/userfiles/files/lilemeraruginifow.pdf
    • https://casabresciani.it/uploads/file/gozupolux.pdf
    • https://sokolzgierz.pl/web/uploads/files/sofozegoluniw.pdf
    • https://www.cibaospalaser.com/wp-content/plugins/super-forms/uploads/php/files/krd3ko0ibldv222r28iobtlp05/tukumiju.pdf
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/160944b90e67c8---37959661806.pdf
    • https://cjsc.se/ckfinder/userfiles/files/xubilukokodowuluxar.pdf
    • https://accuratesearch.com/userfiles/file/2619177491.pdf
    • https://ecohort.com/userfiles/files/wixunijolitilu.pdf
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/160ac1f427c663---84808057594.pdf
    • https://bookatowncar.com/userfiles/file/65019283463.pdf
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c3c4c0e1d60---tuwopemukevobadiluno.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=buying+a+new+construction+home+contingent+on+selling+yours
    • 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_off0000deed.bin
b5de0ce0698ec7bacdde7e7a137427936983357df78fc27856bc22ca994f2f8b
pdf-font-stream PDF embedded font (sfnt) at offset 0xDEED 11028 bytes
font_01_sfnt_off0000f887.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF887 16792 bytes
font_02_sfnt_off00011099.bin
22e56262ca7544748e1c41d32794eacaa763afa446980d331a1a8608edf66f40
pdf-font-stream PDF embedded font (sfnt) at offset 0x11099 17172 bytes