Malicious PDF — malware analysis report

Static analysis result for SHA-256 a24e3a26023181e4…

MALICIOUS

PDF

75.3 KB Created: 2021-09-17 13:32:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: a6852eb3d0625bbccd94dba3fd12b52b SHA-1: 9cf71d4cee316226c1cc95ca42fbbecee51654f8 SHA-256: a24e3a26023181e4d78ce4e36d4872fa7887b59851a8cfb6baa548b95f0b6349
96 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to domains flagged as disposable or potentially compromised CMS upload directories. The ML classifier also strongly indicated maliciousness. While no scripts were extracted, the structure suggests a link farm designed to lure users to other malicious or SEO-manipulated content, likely distributed via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

Heuristics 5

  • 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 http://ggbris.com/slbdavbatala/userfiles/file/42412030079.pdf In PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16130aaf5ccbd1---lexebaxawuwawazodin.pdfIn PDF document text
    • http://luluscafeonline.com/uploads/files/lesazifeluwonaxake.pdfIn PDF document text
    • https://t2sc.me/userfiles/zerutoturunebul.pdfIn PDF document text
    • http://sor1310.com/userfiles/file/kutoledulenatik.pdfIn PDF document text
    • https://used-machinetools.ro/app/webroot/files/userfiles/files/22012830096.pdfIn PDF document text
    • https://shellserva.nl/docs/Image/file/jukebefefup.pdfIn PDF document text
    • http://inbiosa.eu/static/cfiles/files/gixurotibujiv.pdfIn PDF document text
    • http://www.medicellbank.com/userfiles/files/20202354987.pdfIn PDF document text
    • http://youngshiny.com/userfiles/file/1631139538.pdfIn PDF document text
    • https://civilkontroll.hu/uploads/file/kanowifupuliku.pdfIn PDF document text
    • https://dichvuketoanvn.org/uploads/files/berizivax.pdfIn PDF document text
    • http://krakowska98.com/zdjecia/fck/file/bezuwij.pdfIn PDF document text
    • http://phaptangpgvn.net/app/webroot/upload/files/94521246511.pdfIn PDF document text
    • http://nrgmedia.hu/files/file/visaviduditotewuputawadix.pdfIn PDF document text
    • https://pirkitpadangas.lt/ckfinder/userfiles/files/wolapazadawirumep.pdfIn PDF document text
    • http://villabrown.it/userfiles/files/35394889051.pdfIn PDF document text
    • http://ingatlantv.tv/userfiles/files/78161124800.pdfIn PDF document text
    • http://villaturri.it/wp-content/plugins/formcraft/file-upload/server/content/files/16137e598bd141---81086227696.pdfIn PDF document text
    • https://ww150004.linebot.net/upfile/files/20210910062756.pdfIn PDF document text
    • http://begues.mobi/userfiles/file/wepofid.pdfIn PDF document text
    • http://kpdb.org/userfiles/files/lifagovatez.pdfIn PDF document text
    • http://facilitymanagementassociates.com/survey/userfiles/files/97377533111.pdfIn PDF document text
    • https://congtydaihai.com/upload/files/lotadenadilikawolaris.pdfIn PDF document text
    • https://congchung7.com/upload/file/nimopafofe.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/161400309ef2da---48603924304.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=a+little+life+pdf+onlinePDF 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_off0000c4ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4EA 17352 bytes
SHA-256: 189165b6588578bdfe01cd126c883d68d3620ef97605b4fb092c50c89ca612d1
font_01_sfnt_off0000f178.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF178 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001098f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1098F 10044 bytes
SHA-256: 20f763ae94e04ee486032905974f1646b806f689758df2229bbf6a99dded89ee