Malicious PDF — malware analysis report

Static analysis result for SHA-256 631d189b4d3f2a56…

MALICIOUS

PDF

88.8 KB Created: 2021-09-08 23:15:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 4aa6b394fb4f55d7f308a06602fecbc3 SHA-1: 3e2759620938aec02d4db925828bb0327e0214c2 SHA-256: 631d189b4d3f2a56d2613b328460af1178cd76a874879033aae039eba41b0c11
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of a 'utm_term' parameter in one URL further suggests a phishing or scam attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://medvor.ru/uplcv?utm_term=i+want+to+root+my+android+phone PDF link annotation
    • https://saint-florentin.charcutier-traiteur.fr/ckfinder/userfiles/files/27723264693.pdfIn PDF document text
    • http://zhongjiukeji.com/upload_fck/file/2021-9-4/20210904210832790864.pdfIn PDF document text
    • https://mayxaydungthienlong.com/uploads/files/files/28484571215.pdfIn PDF document text
    • https://costabravas.com/uploads/localidades/files/44644362427.pdfIn PDF document text
    • https://gencatakan.com/upload/file/sazutisezizaf.pdfIn PDF document text
    • https://ambient-interier.cz/files/files/64347449163.pdfIn PDF document text
    • https://lolakarimova.uz/ckfinder/userfiles/files/finedigukujopemanuf.pdfIn PDF document text
    • https://myphi.biz/nbloom/fckuploads/file/27248045711.pdfIn PDF document text
    • http://monthclean.com/uploads/files/202109031021533554.pdfIn PDF document text
    • http://99hospitalitygroup.com/ckfinder/userfiles/files/34245328827.pdfIn PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/6e2d975406cda8dba041b8b7cdfc8400/29991533002.pdfIn PDF document text
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135b77fa7e41---bedokowukiwuri.pdfIn PDF document text
    • https://insolite.lu/img/userfiles/files/24482172068.pdfIn PDF document text
    • http://flirdining.com/uploads/files/tizowiponarekujofakexif.pdfIn PDF document text
    • http://workontext.ru/media/file/34439032179.pdfIn PDF document text
    • https://beauty-full.ru/uploads/files/vawonaz.pdfIn PDF document text
    • http://chongqinghaohong.com/upload/files/8903482323.pdfIn PDF document text
    • http://caramelitos.sk/files/xagetodemabanivufute.pdfIn PDF document text
    • http://fipjp.com/userfiles/file/51973616205.pdfIn PDF document text
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/16138415326d2d---galiwokaxiw.pdfIn PDF document text
    • https://jechrina.gr/FCKeditor/userimages/file/zibemivadalam.pdfIn PDF document text
    • https://quangcaowebsite.vn/uploads/files/20945672686.pdfIn PDF document text
    • http://ge-mak.com/files/josubag.pdfIn PDF document text
    • http://gongin.humenia.com/upload/userfiles/2021/09/files/210904225133.pdfIn PDF document text
    • http://rinsacars.com/files/others/lewupujaxesitiges.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_off0000f486.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF486 10596 bytes
SHA-256: a68a1fb26ba82c75035a84404fae495373390ca6acea37d09f0aef6be57c9395
font_01_sfnt_off00010c8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C8F 18588 bytes
SHA-256: 91a7edb02def0761ade3a1a84e12df5861ce543f3e977df7a6697e413b5f23ae
font_02_sfnt_off00013d31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D31 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1