Malicious PDF — malware analysis report

Static analysis result for SHA-256 b891cdef06ac8c1a…

MALICIOUS

PDF

82.1 KB Created: 2021-09-19 10:22:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: ba88ac52e7bc1fcbea6b87460add098c SHA-1: e67bd85bca57d74b7e7684e1dc9bd6aeb1449247 SHA-256: b891cdef06ac8c1a6777945ae6fb179e04ea96d153dbcaf6b5dac825b6c12d3d
204 Risk Score

Malware Insights

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

The sample is a PDF containing embedded JavaScript and numerous links, many of which point to compromised WordPress sites or disposable hosting, suggesting a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly indicate malicious intent. The embedded JavaScript likely facilitates the redirection to malicious URLs, which are the primary IOCs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 8

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://kyea.org/imageuploads/45341697019.pdf In PDF document text
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ec6365e241---44423447554.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ffb36841fa---dejaw.pdfIn PDF document text
    • http://studiosiciliani.eu/userfiles/files/30712490650.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/1612f2d4e3d0c4---xifej.pdfIn PDF document text
    • https://www.abrasco.org.br/ckfinder/userfiles/files/75312390509.pdfIn PDF document text
    • https://www.singaporemedicalclinic.com/ckfinder/userfiles/files/90094108292.pdfIn PDF document text
    • http://niestachow.pl/data/aktualnosci_imgs/file/89101998744.pdfIn PDF document text
    • https://pspgenuine.com/ci/userfiles/files/tiziwozixom.pdfIn PDF document text
    • http://huerural.com/uploads/image/files/jebovimogabegaveto.pdfIn PDF document text
    • http://cdmatik.com/uploads/file/pigejifonizomosazij.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/3343535421.pdfIn PDF document text
    • http://lucidarepavimentimarmogenovaealessandria.it/userfiles/files/50530194810.pdfIn PDF document text
    • http://www.barbazan-debat.fr/ckfinder/userfiles/files/taxirirag.pdfIn PDF document text
    • https://segurosjdd.com/wp-content/plugins/super-forms/uploads/php/files/k06b9vjggpe40gn85cqfvebs12/39017065989.pdfIn PDF document text
    • http://bahtiyardishekimi.com/fckfiles/file/tarazakonazatatokew.pdfIn PDF document text
    • https://aspit.ro/imagini_ws/96401161381.pdfIn PDF document text
    • http://ipcmanpower.com/admin/style/images/userfiles/file/sugezuluberuvadof.pdfIn PDF document text
    • https://www.gurgy.net/ckfinder/userfiles/files/22959970832.pdfIn PDF document text
    • http://congseng.com/uploadfile/files/59218260332.pdfIn PDF document text
    • http://abwfinlay.com/uploads/files/42996591349.pdfIn PDF document text
    • http://carscaso.com/js/upload/files/63772053869.pdfIn PDF document text
    • http://ingegneriarossi.it/userfiles/files/jipudimizudijifudebe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=snapseed+latest+versionPDF 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_off0000dd57.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD57 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f56e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF56E 10524 bytes
SHA-256: 92abed6907fedf55730bfdfefa4ce74c4f2699c9213be916e004643788bb4cb1
font_02_sfnt_off00010d7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D7B 17604 bytes
SHA-256: a1b485180bc245346b617b6b00bcbd216dafe8161dc41c0a067f988e79ff8da2