Malicious PDF — malware analysis report

Static analysis result for SHA-256 81513a27365edec7…

MALICIOUS

PDF

75.3 KB Created: 2021-09-20 04:08:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0b032ea6168c74fd98952fcece5b90f5 SHA-1: 571b8f5feb3a10df4e4b4cfb4147c59cd08828e5 SHA-256: 81513a27365edec7373ddadfbf679f1f64d0076c2a7abc697a66663d51f748c8
196 Risk Score

Malware Insights

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

The sample is identified as malicious by ML classifiers and ClamAV, and exhibits characteristics of a remote support lure. The document's content, though heavily obfuscated in the provided excerpt, is strongly suggested by heuristics to instruct the user to install or connect with a remote support tool. This type of lure is often used to gain unauthorized access to a victim's system, potentially for further malicious activities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Remote-support tool lure high SE_REMOTE_SUPPORT_LURE
    Document instructs the user to install, open, or connect with a remote-support tool such as AnyDesk, TeamViewer, Quick Assist, or ScreenConnect — high-risk in an unsolicited document
  • 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://fandimnarodaku.cz/upload/file/boxakozezaz.pdf In PDF document text
    • https://samavetpharm.com/userfiles/files/255717313.pdfIn PDF document text
    • http://studiosimonepantaleo.it/userfiles/files/pofiguvamimafatolenarej.pdfIn PDF document text
    • https://www.baileysmilk.com/wp-content/plugins/super-forms/uploads/php/files/0a7d4ad0a37f690de26c6cdde92fe67b/62028469659.pdfIn PDF document text
    • https://magnettoptan.com/upload/ckfinder/files/pekudeju.pdfIn PDF document text
    • http://studiopignotti.it/userfiles/files/zazulepuliniv.pdfIn PDF document text
    • http://hotelbelleepoque.bg/userfiles/file/diraj.pdfIn PDF document text
    • http://ansatrans.ru/admin/ckfinder/userfiles/files/tekadavivas.pdfIn PDF document text
    • https://pierrelemagicien.com/userfiles/file/8235725112.pdfIn PDF document text
    • https://stijsr.com/userfiles/file/menamo.pdfIn PDF document text
    • https://kuwaitpolyurethane.com/ckfinder/userfiles/files/lafex.pdfIn PDF document text
    • http://imobilestore.de/userfiles/file/wizotoliva.pdfIn PDF document text
    • http://alhambra.kopanramen.com/uploads/files/xozemejimufugin.pdfIn PDF document text
    • https://harpethvalleypto.org/wp-content/plugins/super-forms/uploads/php/files/713f868f88f925b773fc9a69cb5ee8ef/tinodiwodajevofanidota.pdfIn PDF document text
    • http://snsi.jp/image/news_file/37962353759.pdfIn PDF document text
    • http://tabbanbros.com/admin/fckeditor/editor/filemanager/connectors/upload/file/totokoligefabesevizewe.pdfIn PDF document text
    • http://deeringbayrealestate.com/userfiles/files/digeto.pdfIn PDF document text
    • http://cableesmaltado.com/d/files/pafufuzozeko.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613601a945d6b---55333045778.pdfIn PDF document text
    • https://iphonerepairservice.nl/app/webroot/files/userfiles/files/30351622085.pdfIn PDF document text
    • http://www.klimavill.com/data/editorfile/tiretefuvizupirif.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=android+remote+access+appPDF 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_off0000c26d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC26D 16792 bytes
font_01_sfnt_off0000da7f.bin
594e735a8cd48fe6cf64dfd7eb9930a4abae5adfc9d976c5462043dc3182a49f
pdf-font-stream PDF embedded font (sfnt) at offset 0xDA7F 17428 bytes
font_02_sfnt_off000107e5.bin
0492493c2a5aea2af10c8982d1f502546dad73903319bdbcc4f825c4228574ae
pdf-font-stream PDF embedded font (sfnt) at offset 0x107E5 10608 bytes