Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4ac9a1755acc3af…

MALICIOUS

PDF

88.1 KB Created: 2021-09-09 02:06:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 9e381cb6b8b3f21a7fb14c67f3715f83 SHA-1: a58de43aacfd1178b4a62c9dc4170d4477d6b716 SHA-256: c4ac9a1755acc3af69f9c980ce45438110116e3dc77156d699e8f13fd302f0a9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a large number of external URIs and link farms, many hosted on compromised WordPress sites or disposable domains, indicating a malicious intent to redirect users. ClamAV and ML classifiers also flagged this PDF as malicious, specifically as a phishing trojan. While no scripts were explicitly extracted, the nature of the link farm suggests it is designed to lead users to malicious websites, likely for phishing or malware download.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://synerhu.ru/uplcv?utm_term=unlockmytv+apk+download+2020 PDF link annotation
    • http://omatsuri.kr/data/userfiles/files/joboxukozep.pdfIn PDF document text
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16136afe535e54---rirasudop.pdfIn PDF document text
    • http://jpind.pl/userfiles/file/xazixumi.pdfIn PDF document text
    • http://britishcytology.org.uk/ckfinder/userfiles/files/wexapidowimusixuloxovirux.pdfIn PDF document text
    • http://oris-am.com/editor_up/79908906160.pdfIn PDF document text
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/2e51fa70213484a85f91ad320f700701/verujekopovorofukipogovax.pdfIn PDF document text
    • https://bisleriuber.genefied.co/ckfinder/userfiles/files/66664226307.pdfIn PDF document text
    • http://sentezetutmerkezi.com/upload/ckfinder/files/98138555717.pdfIn PDF document text
    • http://ccforum.kr/uploads/file/1630558806.pdfIn PDF document text
    • https://nhatngudongkinh.phapluatvietnam.com/upload/ckupload/files/tunijipodikozofokikatadir.pdfIn PDF document text
    • https://inlandautorepairmurrietaca.com/wp-content/plugins/super-forms/uploads/php/files/57184109e5696ac19f3fcd9cb0598ad1/11408156643.pdfIn PDF document text
    • http://dentalclinicbangalore.com/uploads/70330102974.pdfIn PDF document text
    • https://serka.com/serka/upload/files/botizeman.pdfIn PDF document text
    • https://eecpowerindia.com/codelibrary/ckeditor/ckfinder/userfiles/files/xotor.pdfIn PDF document text
    • https://le27.fr/docs/file/84290081670.pdfIn PDF document text
    • http://ykzn8.com/upfiles/editor/files/60082466586.pdfIn PDF document text
    • http://www.salpasafarit.fi/tiedostot/files/bufadew.pdfIn PDF document text
    • https://kawanmto.info/contents/files/piviwaladimenewedoriwu.pdfIn PDF document text
    • http://theprofitnesstrainers.com/userfiles/file/71339786003.pdfIn PDF document text
    • https://aodaixuan.vn/app/webroot/upload/image/files/riditasafugifaxolex.pdfIn PDF document text
    • https://www.studiorosaliabusco.it/ckfinder/userfiles/files/54335500786.pdfIn PDF document text
    • http://kor-ra.ru/UserFiles/file/76085534518.pdfIn PDF document text
    • http://icsbc.ru/fuploader/file/bufatoposu.pdfIn PDF document text
    • http://taispacedesign.com/upload/files/lexuzolob.pdfIn PDF document text
    • http://kenzoum.org/home/integrity/public_html/ckfinder/userfiles/files/11641699431.pdfIn PDF document text
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613565a0abaf3---25651979597.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_off0000f21e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF21E 10792 bytes
SHA-256: e84909c6717bcb9bf6d619732ad3d4ab352a1c43f0a0ff45012ff40a3ffd3c4b
font_01_sfnt_off00010b1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B1C 18432 bytes
SHA-256: dcedba0a811aaf480a6d0881d9faaca04c8262c74ea6ef16a05ea66599fda75f
font_02_sfnt_off00013a6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A6F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1