Malicious PDF — malware analysis report

Static analysis result for SHA-256 85f37d88451ef8eb…

MALICIOUS

PDF

77.0 KB Created: 2021-09-09 07:02:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: d30f0919e790e729743022537d063639 SHA-1: 7ef5bd842de78da73aa28367203f9bb19488f243 SHA-256: 85f37d88451ef8ebe5d484d5356d6966b7883f5885bc8c0267236109eefd846a
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous URLs pointing to compromised CMS uploads and disposable domains. These links are likely intended to lure users to phishing sites or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://mimpishio2bet.net/contents/files/wazubikakozezanitudujolu.pdf In PDF document text
    • https://chsins.tw/uploads/files/202109031102551994.pdfIn PDF document text
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/384aa9102789c989a2851b21dbd2e595/terijekuwegaxutaxaten.pdfIn PDF document text
    • https://giraffeng.net/infodaily/gen-ckfinder/userfiles/files/17954451647.pdfIn PDF document text
    • http://jiuxingchaoshi.com/uploads/file/011653328092.pdfIn PDF document text
    • http://strap.sk/uploads/files/88225251731.pdfIn PDF document text
    • http://www.samuitns.com/image/upload/File/83957373376.pdfIn PDF document text
    • http://www.meglobalinc.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1612eaf0ebfeef---72406006937.pdfIn PDF document text
    • http://kingswaytyres.com/project/kingsway/uploads/file/56631850445.pdfIn PDF document text
    • https://negaratoto.com/contents/files/79312035731.pdfIn PDF document text
    • http://heninrealty.com/userfiles/files/lozuvaramuroworete.pdfIn PDF document text
    • https://dgssu.com/upfolder/e/files/20210905081617.pdfIn PDF document text
    • http://matsusushionline.com/uploads/files/xitajitipari.pdfIn PDF document text
    • http://bdsps.org/slbdavbatala/userfiles/file/kuxaniwi.pdfIn PDF document text
    • https://dreamscapes.ca/dream_scapes/userfiles/files/nufoworofe.pdfIn PDF document text
    • http://aktasmatbaacilik.com/resimlerfiles/rapukunijatadanonowijew.pdfIn PDF document text
    • https://davidfoleyinc.com/userfiles/file/49591381370.pdfIn PDF document text
    • http://maxbrio.kr/files/files/nujer.pdfIn PDF document text
    • http://www.siposferenc.hu/html/begelo.pdfIn PDF document text
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137936b7c171---vorojilobizovapesab.pdfIn PDF document text
    • https://gulf-rope.com/images/bulk_images/files/69502799013.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=2+to+5+ratioPDF link annotation
    • 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_off0000cc44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC44 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e45a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE45A 9808 bytes
SHA-256: a0c61a19900124e8a202339f706d494576e5f87481f842b9def6bdfa2a579966
font_02_sfnt_off0000fa09.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA09 17416 bytes
SHA-256: 76ca65dbf3444fc7264fe90104898c6ccccd9a527fa771b43176a0cfe67a3df7