Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6a9342fcedbd757…

MALICIOUS

PDF

70.9 KB Created: 2021-09-26 09:07:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9baeb969cd7b72a77616dbc43b627d5e SHA-1: b54ccfba3e5f9094c26d39a88daf403f87cdbeff SHA-256: a6a9342fcedbd7575935bd6c839eecd8d1ea699d2a509531f1f1981bf611227e
96 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 other PDF files hosted on various domains. Several heuristics indicate this is a link farm, with some links pointing to compromised CMS upload storage. The ML classifier strongly flagged this PDF as malicious, suggesting its purpose is to distribute further malicious content or engage in SEO manipulation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 5

  • 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://bharatdarshan.net/rgroup/ckfinder/userfiles/files/piluso.pdf
    • http://primethailand.com/ckfinder/userfiles/files/pogudaxukafirovurubub.pdf
    • https://vigilanciaweb.cl/dinamicos/files/file/gisupokudaxedebapaf.pdf
    • https://satesayap.com/contents/files/82158035484.pdf
    • http://xn--80aaa6aachkjln0qra.xn--p1ai/ckfinder/userfiles/files/limazujiwilajomud.pdf
    • https://kottayammedicalcollege.org/CMS/ckfinder/userfiles/files/88727333140.pdf
    • http://venkateshservices.com/uploads/pijeg.pdf
    • http://www.1atlanticfunding.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e3feda9ed7---48763930790.pdf
    • http://realestatespoznan.com/uploads/23314247371.pdf
    • https://observatoire-omic.org/documents/file/wesowefurikerodefezi.pdf
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/1614b36d206b0d---novovilofikozulodu.pdf
    • http://tomaszfilipczak.pl/userfiles/file/5729335080.pdf
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/b0fdb6da00a4fbed8b6efc7dac9b714b/kulabefelag.pdf
    • http://www.canadiantreasurer.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130eaa156afc---67554625693.pdf
    • https://emotionalgift.com/ckfinder/userfiles/files/vusevoxopul.pdf
    • http://www.kickcommerce.com/userfiles/file/8570109998.pdf
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613731325af1d---vexusexalesesovidawuwul.pdf
    • https://stmpallet.com/ckfinder/userfiles/files/28645939761.pdf
    • http://studio-rivetti.it/userfiles/files/pitorojagujiwi.pdf
    • https://euforbiabulgaria.gbinvest.net/uploads/pages/files/40956151120.pdf
    • http://stressmanagement-karriere.de/userfiles/file/bojofavejugiwiguve.pdf
    • https://raghuvirtrading.com/userfiles/file/wovigoj.pdf
    • http://wignaccent.com/FCKeditor_2.6.3/userimages/file/20210901173104.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=harvest+moon+gba+rom+download
    • 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_off0000b2ed.bin
a021a7094e7cb23375b71921a1a9b268f6ca34e9d2f21b2610c9a9d37d3c8642
pdf-font-stream PDF embedded font (sfnt) at offset 0xB2ED 10780 bytes
font_01_sfnt_off0000cb92.bin
72cccebb47b4782207d292824d0a78cac70e80e876451be2c3da99544a562863
pdf-font-stream PDF embedded font (sfnt) at offset 0xCB92 16500 bytes
font_02_sfnt_off0000f5ed.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF5ED 16792 bytes