Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3b4455be7855af4…

MALICIOUS

PDF

88.6 KB Created: 2021-08-13 21:48:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c8938dd64223353e234e8707c8728658 SHA-1: 3f1028d4c2dfcb20bc322a1fc18c3b568024ab0c SHA-256: b3b4455be7855af425c99894d3ec7a731aa7b4c2ba7f046b052249d63c9ea546
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The document functions as a link farm, hosting numerous links on compromised WordPress sites, likely to facilitate phishing or malware distribution. The presence of a heuristic indicating a security bypass instruction further supports its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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
  • Security software disable instruction high SE_SECURITY_BYPASS
    Document instructs the user to disable antivirus or security software — unusual for ordinary documents and high-risk in an unsolicited file
  • 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://fastcomputer.vn/wp-content/plugins/super-forms/uploads/php/files/3f9f44e513dcd414320ebbaf5f0e9e54/33609150338.pdf
    • http://mujuerp.com/uploads/ckeditor/files/20210616084126.pdf
    • https://thejinglelab.com/wp-content/plugins/super-forms/uploads/php/files/kfer2tutqcg4bu6vgjhmi1g4ud/vipomolatidi.pdf
    • https://baoholaodong24.com/userfiles/file/63708810435.pdf
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/160fedbdba75d8---fisuxinititopovelimeta.pdf
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/4f5e0aab3096b7f71060dc366610df7e/zoxumurajukuzun.pdf
    • http://delvalle68.com/clients/54584/File/30678216609.pdf
    • http://www.morenoroofing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e029d5a053b---wefofu.pdf
    • http://195exim.com/datas/files/jigepavazusafumofewiwet.pdf
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608042b2063a9---76586594643.pdf
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f6bae8aabc---nagosawagolepoporato.pdf
    • http://coatsofarms.com.au/ckfinder/userfiles/files/velexanisudanenunuki.pdf
    • http://elijahlaurabishopblack.com/clients/b/be/bed082b287f5bb70db4763ab929fc18a/File/zomipiwawivobabekojabozu.pdf
    • http://zovsh.com/Uploadfiles/files/23794317449.pdf
    • https://arizonapoolcontractor.com/wp-content/plugins/formcraft/file-upload/server/content/files/160962b27e97f7---71238492984.pdf
    • http://sarica.com.tr/ckfinder/userfiles/files/89103595665.pdf
    • http://ngpsusa.com/wp-content/plugins/super-forms/uploads/php/files/1r290tvogck2ejhettnmuaraan/pilafalutiropadavimutosaw.pdf
    • http://traiteur-ribot.fr/userfiles/file/88454164588.pdf
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1610dfc076e0d9---kofajarapilorofujufugu.pdf
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/75b28d20916322954e93ed478034b367/bavodoluzez.pdf
    • https://vinamex.info/uploads/news_file/vutojewegisalelora.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=nck+dongle+spd+crack+2020
    • 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_off0000f64f.bin
96076e6ff0b41845d987c688ee1fe2bbb477fd7aa1b64fbdad1aee45651dd9fd
pdf-font-stream PDF embedded font (sfnt) at offset 0xF64F 17460 bytes
font_01_sfnt_off0001242d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1242D 16792 bytes
font_02_sfnt_off00013c44.bin
8311c255f2af9333a857b791d2177f5170160b498bcad3f49aa33a40a96212fa
pdf-font-stream PDF embedded font (sfnt) at offset 0x13C44 10808 bytes