Malicious PDF — malware analysis report

Static analysis result for SHA-256 a244f3c918c1d0c9…

MALICIOUS

PDF

70.2 KB Created: 2021-10-03 10:32:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 66690c99fbd270569e2ca61e378e78da SHA-1: 0970041aeb107269d35b0b5abdcbe5366b977b27 SHA-256: a244f3c918c1d0c990b689678ac1475ef50e5ec95619d56b53857313ce9f88f5
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate the document functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS platforms. The presence of numerous unknown-reputation URLs suggests an attempt to distribute malicious content or phish for credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9837

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 https://huntic.ru/uplcv?utm_term=how+to+insert+page+on+pdf PDF link annotation
    • http://thunderstar.cn/userfiles/file/20210925010535568360225.pdfIn PDF document text
    • https://www.hkha.org/ckfinder/userfiles/files/90254652354.pdfIn PDF document text
    • http://dulichtantai.com/files/uploaded/files/79561272020.pdfIn PDF document text
    • http://tongchangkj.com/uploadfile/file///2021092909562511.pdfIn PDF document text
    • http://abwvictory.com/uploads/files/54776381226.pdfIn PDF document text
    • http://abwninemile.com/uploads/files/73480952099.pdfIn PDF document text
    • https://simbhaolipower.com/images/file/90867873499.pdfIn PDF document text
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/529e535ad7085a447fe863c559a648eb/tiwobi.pdfIn PDF document text
    • http://lisaarkinlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/81002793029.pdfIn PDF document text
    • http://ubest.ru/images/file/gokugov.pdfIn PDF document text
    • http://rajskiewakacje.pl/userfiles/file/74588953199.pdfIn PDF document text
    • http://studiomanzetti.it/userfiles/files/putemazusudojowalexatet.pdfIn PDF document text
    • http://nd-58.ru/wp-content/plugins/super-forms/uploads/php/files/ba9e2ad3bc80dda9e151c87a71ae237f/81612271245.pdfIn PDF document text
    • https://wintechindia.in/ckfinder/userfiles/files/ratiduvulofuwo.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1614b73efb0401---37199393448.pdfIn PDF document text
    • http://a1-automotivegroup.com/upload/files/lepavosopagesijunegizuwe.pdfIn PDF document text
    • http://hpcad.pl/Upload/file/sisijapuburagege.pdfIn PDF document text
    • http://jlssj.com/qianzi/upfile/case_editor/file/mexubonubip.pdfIn PDF document text
    • http://rotang.net/userfiles/file/futetidesadetotuwa.pdfIn PDF document text
    • https://saleskerala.com/ckfinder/userfiles/files/bigidudesuse.pdfIn PDF document text
    • https://www.artikel238.nl/emmwebbit/resources/ckfinder/userfiles/files/58243896946.pdfIn PDF document text
    • http://sungwoo-n.com/userfiles/file/11913226361.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/16158f7d109799---xaxupamuzajubisexutenasa.pdfIn PDF document text
    • http://compow.net/ckfinder/userfiles/files/13093727166.pdfIn PDF document text
    • https://halkum.rs/files/56333157603.pdfIn PDF document text
    • http://townofwinslowin.com/flash/townofwinslowin.com/file/tiretazazusujotikifep.pdfIn PDF document text
    • https://dongciao.com/uploads/files/202110030011094220.pdfIn PDF document text
    • http://laarakkers.com/ckfinder/userfiles/files/57465474247.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b43c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB43C 15172 bytes
SHA-256: 1b6967b3ccf2094ca499b3702cfcb4f92a6b356318346a2f141bc1df64029895
font_01_sfnt_off0000da80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA80 10704 bytes
SHA-256: 46d013bc8e0e236034b8348aa8a59611659a43996203ff389af6f41642bce7e1
font_02_sfnt_off0000f305.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF305 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1