Malicious PDF — malware analysis report

Static analysis result for SHA-256 966e669d7795b834…

MALICIOUS

PDF

83.8 KB Created: 2021-09-01 15:04:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: c33fd3fe1e2e16b4b1787f6fbf6f1990 SHA-1: 87ca2f870e1de7294660824138a3e72e8e058b3e SHA-256: 966e669d7795b8346bb85a77885c9f32eac3a88403029ceb664183ff2fa3c181
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains a link farm pointing to numerous external URLs hosted on potentially compromised CMS uploads and disposable hosting, indicating an attempt to redirect users to malicious sites. The presence of embedded URLs and the nature of the heuristics suggest the PDF is intended to facilitate initial access via spearphishing, likely leading to further stages of infection.

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 http://mail-ex.net/userfiles/file/vapijutawajomose.pdf In PDF document text
    • http://www.gyndoktors.de/ckfinder/userfiles/files/4083168354.pdfIn PDF document text
    • http://dienlanhtruongson.com/upload/files/nepifejuvikirikej.pdfIn PDF document text
    • http://high-keenltd.com/userfiles/file/74622414673.pdfIn PDF document text
    • http://www.sphotobooth.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f305b246ae---texetisu.pdfIn PDF document text
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160774b4c0d24d---vuredizufutevidiwagib.pdfIn PDF document text
    • https://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/5tn57qdo7e3gm4s6eqq9tmno9j/guworesag.pdfIn PDF document text
    • https://festivalecolo.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a5fc3fa3f4f---jatajifobolo.pdfIn PDF document text
    • https://rimi.sk/userfiles/file/50651678184.pdfIn PDF document text
    • https://montpellier-business-plan.com/mbp/upload/images/images/upload/ckfinder/73129396759.pdfIn PDF document text
    • https://nikosdimos.gr/userfiles/file/2459973111.pdfIn PDF document text
    • https://simondaulte.com/ckfinder/userfiles/files/tofakovuzilud.pdfIn PDF document text
    • http://www.ellisrasbetonwerke.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160b0a9826a92f---ramopobatedovanunikek.pdfIn PDF document text
    • http://rexant.by/upload/editor/files/jipobaw.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a6fd59e607---9169983512.pdfIn PDF document text
    • http://el-system.jp/uploads/2012/files/67323646960.pdfIn PDF document text
    • https://bawaniint.com/ckfinder/userfiles/files/25442129597.pdfIn PDF document text
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/a9d691a035532a677c904b79927037bb/kubine.pdfIn PDF document text
    • http://sskj.pl/userfiles/file/50151489830.pdfIn PDF document text
    • https://aluminiosarla.com/userfiles_arla/files/73829329076.pdfIn PDF document text
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ddfc5ee54b---kepofurafibogijukowe.pdfIn PDF document text
    • https://ddshower.com/ckfinder/userfiles/files/zewakosisedulubeti.pdfIn PDF document text
    • http://rufullthrottle.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608fd1109855c---puxiberixer.pdfIn PDF document text
    • https://actorconseil.com/files/file/98278728307.pdfIn PDF document text
    • https://aslimitada.com/userfiles/file/kimujuvemil.pdfIn PDF document text
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/c2758773b3ac50abd51e3df4db787786/49423695115.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=lowest+common+multiple+of+6+and+20PDF 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_off0000dbd1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBD1 19260 bytes
SHA-256: 21bb3d90575b2f11721ec49dffe54673e6bb61889b70489224009558eac70b33
font_01_sfnt_off00010ef2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EF2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012709.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12709 11232 bytes
SHA-256: 1ff26a0757cc4ab74641c5c6625885b83f3e66560644521401609d31cb1aeae4