Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f28de4234048188…

MALICIOUS

PDF

81.5 KB Created: 2021-10-06 01:44:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 208f71f7c679a26b05b1e24c3070002d SHA-1: 29eb4ce02a00f1a7f1314a2df9fd7d55b8304d29 SHA-256: 4f28de423404818864651c0c673e892aa38936a7b882aff5f6b4b223d1dbf944
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. The presence of external URI heuristics and link farm indicators further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://gptools.net/userfiles/file/73736497714.pdf In PDF document text
    • http://ttmm.co.jp/ckfinder/userfiles/files/14017370017.pdfIn PDF document text
    • https://seedomoretravel.com/files/files/zaxixa.pdfIn PDF document text
    • http://congseng.com/uploadfile/files/dikawigulot.pdfIn PDF document text
    • http://studiosiciliani.eu/userfiles/files/zidiz.pdfIn PDF document text
    • http://sieuthibongda.net/ckfinder/userfiles/files/58087880116.pdfIn PDF document text
    • https://saikekanglun.com/filespath/files/20210917133322.pdfIn PDF document text
    • http://www.bridalchapel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161542f0aa0dc8---83656930782.pdfIn PDF document text
    • https://queensflower.nl/clientfiles/kosodupida.pdfIn PDF document text
    • http://www.guus.edu.mn/ckfinder/userfiles/files/kakezumuparo.pdfIn PDF document text
    • https://questfran.com/broker-site/files/files/2092340511.pdfIn PDF document text
    • http://silarperu.com/UserFiles/file/beputu.pdfIn PDF document text
    • http://podwierzba.eu/ckfinder/userfiles/files/nojixijorikew.pdfIn PDF document text
    • http://www.miamiairportlimo.net/wp-content/plugins/formcraft/file-upload/server/content/files/16151c280ac82b---junabebovebapake.pdfIn PDF document text
    • https://olivermilk.vn/tctt/sites/aaa/file/zolejisuzelireve.pdfIn PDF document text
    • http://s2ipower.com/survey/userfiles/files/6835285521.pdfIn PDF document text
    • http://pm-ural.com/uploads/files/19323301961.pdfIn PDF document text
    • http://safeabortionnepal.com/userfiles/file/56657115749.pdfIn PDF document text
    • https://maidintown.co.uk/wp-content/plugins/super-forms/uploads/php/files/1f680494aaf4609c65561e13697ec430/xukilezasotifekemer.pdfIn PDF document text
    • http://women-for-marriage.com/ckfinder/userfiles/files/botivo.pdfIn PDF document text
    • http://moveworldtogether.com/datas/files/80710076314.pdfIn PDF document text
    • http://ssatripoli.org/userfiles/file/vopedobekiname.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=amharic+bible+download+pdfPDF 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_off0000d086.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD086 21440 bytes
SHA-256: b640a3acd73db50db3fcf3c938cb8605ca2f84ecd7604114ee781374664b43a6
font_01_sfnt_off000107f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107F6 10828 bytes
SHA-256: 0dc9df579e3ab8f1b4271c4ccc5b9b232da866184dce382d2cc951bb19b928c5
font_02_sfnt_off00012089.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12089 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1