Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa5ba057850d4274…

MALICIOUS

PDF

72.4 KB Created: 2021-09-21 20:21:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 7c8fdfb20e02c70ffecf81ad464bb6bd SHA-1: 2bd722013c572c16c1592a06b8476ddc0ea3fd52 SHA-256: aa5ba057850d427436e555d61e29a9dd449263fdf5ae0bdc783cbf4b16234537
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised CMS upload directories, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly support its malicious nature. The presence of multiple external URIs and link farm heuristics confirms the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://ecilingirler.com/resimler/files/58038884734.pdf In PDF document text
    • https://basisangka.com/contents/files/51921841978.pdfIn PDF document text
    • http://anhhieu.vn/hinhanh/file/pukapobiwuguzowezaweje.pdfIn PDF document text
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613a06b763b8a---27102413348.pdfIn PDF document text
    • http://bakoca.hu/files/file/81942043422.pdfIn PDF document text
    • http://www.rebranded.tv/wp-content/plugins/formcraft/file-upload/server/content/files/16144e95254f6c---452237683.pdfIn PDF document text
    • https://jdrum-music.com/uploads/ckfiles/files/66498768734.pdfIn PDF document text
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/189ce61192d8f28a69970935484f15bc/nokizigafonidujo.pdfIn PDF document text
    • http://makesomenoise.hu/upload/file/18690093164.pdfIn PDF document text
    • https://myshalewell.com/userfiles/file/66968366951.pdfIn PDF document text
    • http://benetalent.com/upload/files/donipetujiwilinobisaj.pdfIn PDF document text
    • http://studioindelicato.com/userfiles/files/vemezuluvebunaxatuw.pdfIn PDF document text
    • http://naoshima-habitant.com/images/blog/file/7362495079.pdfIn PDF document text
    • http://hodinovysoused.cz/upload/file/bazaxabakivakos.pdfIn PDF document text
    • http://rivebistro.net/ckfinder/userfiles/files/dukaxevotaxezuxesurus.pdfIn PDF document text
    • http://kuwaited.com/cote_dor_import/admin/ckfinder/userfiles/files/kemoritumuxekexovakit.pdfIn PDF document text
    • http://businessvaluationapp.com/fck_files/file/62697341104.pdfIn PDF document text
    • https://www.clubmanizales.com.co/wp-content/plugins/formcraft/file-upload/server/content/files/16133bf8baf505---81365214840.pdfIn PDF document text
    • http://styrexon.cz/userfiles/file/57742231311.pdfIn PDF document text
    • http://gdlejia.com/uploadfile/files/20210909_024932.pdfIn PDF document text
    • https://natyabio.com/uploadfiles/kigut.pdfIn PDF document text
    • http://simoncaulkin.com/images/geredalozodof.pdfIn PDF document text
    • https://korzo-galeria.hu/files/file/33922580498.pdfIn PDF document text
    • http://magyaringatlanadatbazis.hu/dev/_user/file/25691430106.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=redmi+note+9+android+autoPDF 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_off0000b825.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB825 17372 bytes
SHA-256: f4ef0b0d7475e8426efc5a9315ce15d8b7adffbcec1dcf971af139252c647481
font_01_sfnt_off0000e43b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE43B 10508 bytes
SHA-256: 2619065e89d237910096c0b1281739b7c2b3c000708f06ad167ebd13529325ee
font_02_sfnt_off0000fc2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC2A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1