Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a31c19b6b9f2f41…

MALICIOUS

PDF

85.5 KB Created: 2021-09-21 20:30:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 34630b5bf19e0123741ce4cef98cf511 SHA-1: 43a17489980532637e5f3714d6b8809a575eeefe SHA-256: 8a31c19b6b9f2f41f8a4479caccec3341a12ede8a5f12d388214ba7fd73d6179
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It functions as a link farm, containing numerous URLs that point to potentially compromised websites or disposable hosting. The presence of these links suggests an attempt to redirect users to phishing sites or download further malicious content, aligning with the 'Spearphishing Attachment' technique.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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 https://huntic.ru/uplcv?utm_term=c%C3%A1ch+chuy%E1%BB%83n+danh+b%E1%BA%A1+t%E1%BB%AB+iphone+sang+android PDF link annotation
    • https://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/5a3154539547cee7035445717b688090/51422678828.pdfIn PDF document text
    • https://fotojursa.cz/userfiles/file/niwogonijokaradiw.pdfIn PDF document text
    • https://suativisamsungtaihanoi.net/upload/files/28973214986.pdfIn PDF document text
    • http://przychodnia-felinskiego.pl/uploads/editor/file/74409335066.pdfIn PDF document text
    • http://alpha-cp.com/userfiles/file/24899064957.pdfIn PDF document text
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/b8e6fp4c3ngbq2a30h23gc6pse/57344449903.pdfIn PDF document text
    • http://zkmeiqi.com/admin/ckfinder/upfile/files/93810388941.pdfIn PDF document text
    • http://majortaylorride.info/images/uploaded/file/44443359883.pdfIn PDF document text
    • http://almawred-sy.com/files/adminfiles/files/sagemiviruje.pdfIn PDF document text
    • http://air-con.ru/upload/files/41099886434.pdfIn PDF document text
    • https://geya99.com/ckfinder/userfiles/files/penopagetitokavedam.pdfIn PDF document text
    • http://mibenjamin.com/userfiles/file/gonatevifovunapalowawu.pdfIn PDF document text
    • http://www.xpresswedding.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613dc11c3ab45---berumiwomugekivifabu.pdfIn PDF document text
    • https://rijst.nu/userfiles/file/71618908127.pdfIn PDF document text
    • https://vinadesigndanang.vn/uploads/image/files/wowefuwilubigoruvupaw.pdfIn PDF document text
    • http://lasantitosrestaurant.com/userfiles/file/dufodofukujotut.pdfIn PDF document text
    • https://igescanada.com/ckfinder/userfiles/files/30502386607.pdfIn PDF document text
    • https://guruvinodji.com/Userfiles/file/lumeregenakuxowubabo.pdfIn PDF document text
    • http://s2ipower.com/survey/userfiles/files/26312989496.pdfIn PDF document text
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/jlq5oqdlu1e1s3np746u5joij7/315259936.pdfIn PDF document text
    • https://semagro-msw.ru/pics/images/file/18753106466.pdfIn PDF document text
    • https://dubigroup.com/admin/fckeditor/editor/filemanager/connectors/upload/file/1577700730.pdfIn PDF document text
    • 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_off0000dba0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBA0 11952 bytes
SHA-256: 80e4a31137348624f8b52964c506c8465e8e3fba2b5499a5af956f7b3502c1f5
font_01_sfnt_off0000f6a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6A9 27672 bytes
SHA-256: f8a06be44cb1e9dc5476781fd29f46b07d9c6ef01b5e6432a6e50f3bd45967f6
font_02_sfnt_off00012d9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D9B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1