Malicious PDF — malware analysis report

Static analysis result for SHA-256 40f05c7845ba5a8f…

MALICIOUS

PDF

87.2 KB Created: 2021-09-24 03:30:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5db98b9a3b9f99eaaa9952fb867cca44 SHA-1: 98b52c282cf44b56e622ab47a90300015770f153 SHA-256: 40f05c7845ba5a8fdcfffcf6bf614ba378b39a60e41d63439bea7e40db33000f
156 Risk Score

Malware Insights

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

The PDF contains numerous external URIs and link farm heuristics, indicating it's designed to redirect users to potentially malicious sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. The presence of compromised CMS upload links further supports the malicious nature of the hosted content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://krisoc.ru/uplcv?utm_term=summon+night+gba
    • http://handbook.hu/upload/page/file/bosizuzerotezipe.pdf
    • https://bccphil.paramedix.biz/uploadfiles/file/nowixeji.pdf
    • http://shopcode.ru/uploads/file/wejolufivigodilumu.pdf
    • http://www.hptindia.com/wp-content/plugins/formcraft/file-upload/server/content/files/161409600c2e62---13049733392.pdf
    • http://makaeximworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614766820eaeb---lutunadino.pdf
    • http://makairways.in/home/makairways2017/public_html/dowalumniusa/ckfinder/userfiles/files/3481742750.pdf
    • https://kcharp.com/ckfinder/userfiles/files/58465365329.pdf
    • http://bubb.cn/up_file/file/74907597407.pdf
    • http://innotack.com/userfiles/files/89858316192.pdf
    • http://vtaky.sk/media/file/64500909259.pdf
    • https://dreamscapes.ca/dream_scapes/userfiles/files/gosiwonikimoburim.pdf
    • http://eikenhorstgroep.nl/userfiles/file/77060358644.pdf
    • https://sklep-pinokio.pl/web/uploads/files/lewaviforasasogiwet.pdf
    • http://harchovyk.com/userfiles/file/fakawola.pdf
    • http://etabetasurvey.com/userfiles/files/31867747218.pdf
    • http://xn--vb0b83rba554gca.kr/page_data/file/20210903175352.pdf
    • http://focalthai.com/file_media/file_image/file/saxibovujipafadaz.pdf
    • http://nb-magnet.com/upload/files/48367217157.pdf
    • http://elektrostroy.kz/ckfinder/userfiles/files/fuparuvokefufabi.pdf
    • http://hansungidschool.com/userfiles/file/7922533740.pdf
    • http://kstarsmall.net/userfiles/file///dogaxamimawajoke.pdf
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c4aad547be---pidexeruwasuxan.pdf
    • https://karolinanowak.com/userfiles/file/wagud.pdf
    • http://www.saaegfpolis.org.br/ckfinder/userfiles/files/51062861877.pdf
    • https://cullinanconstruction.com/wp-content/plugins/super-forms/uploads/php/files/ebg7it5cg1sa6e38c9f0dvjipt/27853947237.pdf
    • http://www.temaricerca.com/entry2013new/admindia/ckfinder/userfiles/files/14810456209.pdf
    • http://minisadik-margaritka.ru/admin/ckfinder/userfiles/files/ruzexajutar.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e979.bin
e437d56a4a153f880d674a0790460a3480eea2b96ef5e6e403c09653e11ff2ba
pdf-font-stream PDF embedded font (sfnt) at offset 0xE979 20456 bytes
font_01_sfnt_off00011f5f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11F5F 16792 bytes
font_02_sfnt_off00013776.bin
46fe7b7e0616ad0b70c68c8fe24d7240d2cee2f404ced7b6f4dde8e010b63dba
pdf-font-stream PDF embedded font (sfnt) at offset 0x13776 10424 bytes