Malicious PDF — malware analysis report

Static analysis result for SHA-256 8ac55cb97cf21716…

MALICIOUS

PDF

80.3 KB Created: 2021-10-13 14:59:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: b4a3fc5000f06a762a35c37004f8d8c3 SHA-1: e9ca3bdebc1e58488bc6ef2c8dd03b6dbd17dd37 SHA-256: 8ac55cb97cf2171624280b6a3d414f3632f638c00d8c3c8a98690bcb6be812c5
156 Risk Score

Malware Insights

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

The PDF contains a link farm directing to multiple domains, with several URLs pointing to compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, and the document body was unreadable, but the URL analysis and heuristic firings are sufficient for this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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 http://daiichihousing.net/uploads/news_file/tumebagitedugiziwan.pdf In PDF document text
    • https://armature.ir/cache/fck_files/file/pumuberijorazujon.pdfIn PDF document text
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/c26d382e2055899e54d0bf0f45a45f8d/5149329938.pdfIn PDF document text
    • http://nbnjl.com/userfiles/files/dulakevomexikisoropoti.pdfIn PDF document text
    • http://alpinist.store/sribati/editor/uploadfiles/xofotuzuki.pdfIn PDF document text
    • http://beloezoloto.ru/userfiles/file/dekepesusi.pdfIn PDF document text
    • https://mcq-exambd.bdbabymart.com/app/webroot/ckfinder/userfiles/files/powozugowoz.pdfIn PDF document text
    • http://abwingsbuffalo.com/uploads/files/31591930314.pdfIn PDF document text
    • https://www.grandeprairie.org/wp-content/plugins/formcraft/file-upload/server/content/files/161585df0256e1---gamokololuvuwego.pdfIn PDF document text
    • http://rocincorporated.com/domain.com/images/dynamic_pages/file/82696052633.pdfIn PDF document text
    • https://njshore.drinkpoint.com/uploads/files/36983838173.pdfIn PDF document text
    • https://artedeeducar.com.br/ckfinder/userfiles/files/8856427521.pdfIn PDF document text
    • http://anabakorea.jp/userfiles/file/minobewafika.pdfIn PDF document text
    • https://medius.sk/userfiles/file/72133768399.pdfIn PDF document text
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16146ffbdb67f7---59188276530.pdfIn PDF document text
    • https://betalinktech.com/blmedia/file/ratirul.pdfIn PDF document text
    • https://avenue102.com/uploads/file/53099758261.pdfIn PDF document text
    • http://secondary.oksalesstore.com/uploads/assets/files/jipejonibipokotasono.pdfIn PDF document text
    • http://balade-pierry.fr/userfiles/file/demuv.pdfIn PDF document text
    • http://richmediahouse.com/admin/uploads/file/46839343585.pdfIn PDF document text
    • https://duhocblueocean.vn/ckfinder/userfiles/files/82783640911.pdfIn PDF document text
    • https://probidjp.com/ckfinder/userfiles/files/20210925_161003.pdfIn PDF document text
    • http://subventionsbetrug.de/wp-content/plugins/super-forms/uploads/php/files/vmmjsut4qlrtftt91qq0s4otsl/98687458150.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Gsjc/~3/896FEnmJZlk/uplcv?utm_term=paramore+you+are+the+only+exception+chordsPDF 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_off0000cf22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF22 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e739.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE739 11096 bytes
SHA-256: 54a760731f72e5f944bc16d90dd8840145843c581a7162523b81fcb69e450804
font_02_sfnt_off000100eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100EB 19408 bytes
SHA-256: bb49ac7f32632ec3e80bd8a67642eaef04f372cdfd2cf986fe44999f3f789a17