Malicious PDF — malware analysis report

Static analysis result for SHA-256 efdb985cbb823f05…

MALICIOUS

PDF

86.2 KB Created: 2021-09-20 03:43:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 1229f829619a04a4349f1f8ca735ffbd SHA-1: ba55c0f2824e0e911fb4d1deb59170a5cfdd640c SHA-256: efdb985cbb823f057a739aad2f396cabf98ca6723db8cf65e1caeaa5f0b72fe1
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by ML classifiers and ClamAV as malicious. It contains numerous embedded URLs, many of which point to suspicious PDF files on various domains, suggesting a link farm or phishing lure. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a pattern of using disposable hosting for a large number of links, further supporting a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://cnzhongkui.com/fckeditor/editor/filemanager/connectors/php/uploads/file/061151565188.pdf In PDF document text
    • https://szpital-sulecin.pl/images/fckfiles/file/tovovezolamagejef.pdfIn PDF document text
    • https://bizimpin.com/calisma2/files/uploads/wufaguf.pdfIn PDF document text
    • http://ar-intl.net/wp-content/plugins/super-forms/uploads/php/files/4feisr7uhspce82qslqeusg9l6/52120725287.pdfIn PDF document text
    • http://studiotecnicobonoli.com/userfiles/files/tizizi.pdfIn PDF document text
    • https://www.pirkitpadangas.lt/ckfinder/userfiles/files/7113610217.pdfIn PDF document text
    • http://bolt-go77.com/fckeditor/userfiles/file/64503565531.pdfIn PDF document text
    • http://kosmonautika.ee/ckfinder/userfiles/files/8217119126.pdfIn PDF document text
    • http://noithatnhapkhaugiasi.com/luutru/files/55678043384.pdfIn PDF document text
    • https://meritumptt.pl/dokumenty/file/kujorovuti.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16134698d8aa44---1984899000.pdfIn PDF document text
    • http://turskazka.ru/ckfinder/userfiles/files/wasiwiruzabagotujaf.pdfIn PDF document text
    • https://yourwebcenter.com/files/file/luture.pdfIn PDF document text
    • https://textmakareknutsson.se/upload/image/21255912414.pdfIn PDF document text
    • https://namphuctourist.com/userfiles/file/27022050274.pdfIn PDF document text
    • http://bidwoodmachine.com/d/files/zufuvipowijafajinepe.pdfIn PDF document text
    • http://zlhk.ru/upload_picture/file/97454290637.pdfIn PDF document text
    • https://institut-arabe.org/ckfinder/userfiles/files/18966055863.pdfIn PDF document text
    • http://vrieshorst.nl/images/uploads/file/76166115386.pdfIn PDF document text
    • http://handbook.hu/upload/page/file/nawimelezalogosovobezefo.pdfIn PDF document text
    • https://e-room.co/userfiles/file/97348969203.pdfIn PDF document text
    • http://www.companyforte.com/imagenes/editor/file/52230335771.pdfIn PDF document text
    • http://arcomproltd.com/userfiles/file/83615001762.pdfIn PDF document text
    • http://haiqi-machine.com/d/files/supefiradofekenaposu.pdfIn PDF document text
    • http://www.somdattabasu.com/fckimages/file/vuxufet.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=man+of+steel+zack+snyder+cutPDF 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_off0000eb69.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB69 10736 bytes
SHA-256: 904fd5b711be902a42ea22cdfa90c40b08a64d406c4091cd830f5f90021c4726
font_01_sfnt_off00010459.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10459 18112 bytes
SHA-256: f90bab83d1fb307c3dfe5e99b7ae78c5571d933186b0afec55d43e18ffa91201
font_02_sfnt_off000132d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x132D3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1