Malicious PDF — malware analysis report

Static analysis result for SHA-256 efc6fca0c4c729e8…

MALICIOUS

PDF

87.0 KB Created: 2021-09-23 19:19:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: b830a74c8a687a520fde7e5d9c010eb8 SHA-1: 3e1d9f3243d48f9780d7dfe73b0a61d3d4bcd739 SHA-256: efc6fca0c4c729e8e61bfb4a60e8075e18348b1625993c364c0a8d53ec6e6218
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript and a large number of external URIs, many of which point to compromised websites or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The embedded JavaScript is likely responsible for redirecting the user to these malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9922

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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 https://smidgel.ru/uplcv?utm_term=bike+race+unlimited+money PDF link annotation
    • https://bilalyapidekorasyon.com/userfiles/file/kokoxusewogimexedanid.pdfIn PDF document text
    • http://sonhanint.com/uploadpic/sun/files/202109100803439860.pdfIn PDF document text
    • http://pitchdecor-construction.com/user_img/files/razoboxomojosawa.pdfIn PDF document text
    • https://bgg.pirkitpadangas.lt/ckfinder/userfiles/files/zilojazuvekorumelapos.pdfIn PDF document text
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/7477815b1a7e8baf53f65f6d5e0569b7/51212364186.pdfIn PDF document text
    • https://arrad.ch/modules/ck/ckfinder/userfiles/files/vomurosemumezonug.pdfIn PDF document text
    • http://carrozzeriabosini.net/userfiles/files/87779949049.pdfIn PDF document text
    • http://around-sicily.net/userfiles/file/kusorezujiveli.pdfIn PDF document text
    • http://langmoon.jp/js/upload/files/89502191487.pdfIn PDF document text
    • http://art-ball.net/files/file/ralenudebixobuvolesagibiv.pdfIn PDF document text
    • http://palletgoanloi.com/img-dn/files/93480259685.pdfIn PDF document text
    • http://evola.it/userfiles/files/60959689516.pdfIn PDF document text
    • https://spvi.cn/filespath/files/20210909150806.pdfIn PDF document text
    • https://monarchwinemerchants.com/wp-content/plugins/super-forms/uploads/php/files/f70f113a0c20a469d21f7035b9d2b537/lorutedijexovaxisixut.pdfIn PDF document text
    • http://kcwoman.medsoft.kr/pds/userfiles/files/biluzesawe.pdfIn PDF document text
    • http://group-anons.ru/userfiles/files/22769147737.pdfIn PDF document text
    • http://indyztyle.com/ckfinder/userfiles/files/xejililejebulemodip.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/161320a5458708---44598236643.pdfIn PDF document text
    • http://www.sbawerribee.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16147bcdb60ea0---54127503980.pdfIn PDF document text
    • https://businesslife.com/content/files/85373789818.pdfIn PDF document text
    • http://hwangtosidae.com/userData/ebizro_board/file/9114581922.pdfIn PDF document text
    • https://thefertilizerequipment.com/d/files/41093802519.pdfIn PDF document text
    • http://lex-ter.ru/admin/ckfinder/userfiles/files/zireserobofopuraforeju.pdfIn PDF document text
    • https://a-metal.e-giant.net/archive/file/files/6535870645.pdfIn PDF document text
    • https://soi.icami.mx/ckfinder/userfiles/files/tugum.pdfIn PDF document text
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d8ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8FF 17672 bytes
SHA-256: 430e0ee37aa5efe15396137814705450976a0a495a12be2cdbe4a68b7e8bcd7a
font_01_sfnt_off000106e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106E4 16388 bytes
SHA-256: 3cecd24d7d326d46f8cf5f840d8834f03ec79f9ce2b3cbe15e01b9885af29c80
font_02_sfnt_off00011d81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D81 10720 bytes
SHA-256: ae7b48d1640954441b379ffbb1837c7a9d6eaa3d430ee3f7e4a190c84bc1fdea
font_03_sfnt_off00013622.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13622 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1