Malicious PDF — malware analysis report

Static analysis result for SHA-256 fc88186853f9ee7e…

MALICIOUS

PDF

80.8 KB Created: 2021-06-30 12:26:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e601d69c0ad42107e9907997adf1d7c1 SHA-1: ca0efebad547d54d57213912867874bcbdc1b3fa SHA-256: fc88186853f9ee7e19262e75a43de04894fb66e1022cfbf8567db8f28177ed6b
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URIs pointing to compromised WordPress upload directories and disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The PDF structure itself is also flagged for duplicate object bodies, a common obfuscation technique in malicious PDFs.

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 https://philabc.ru/uplcv?utm_term=i+am+number+four+series+order
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160796bff118b5---zuwuwuv.pdf
    • https://event-connections.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608551e4b776b---23344138611.pdf
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082a1c63cf07---gedotuxedogopiw.pdf
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/160bd4fe9a376c---38929574074.pdf
    • http://www.absolutecateringla.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae6f24531fa---navokexijo.pdf
    • http://edwardnugent.com/userfiles/files/buzexite.pdf
    • http://gdgom.com/upload/file/210615020113309136g0ngsg33lc12.pdf
    • https://www.endthestigmacounselling.com/wp-content/plugins/super-forms/uploads/php/files/n7mb8e0q6gvfbppev85o3ftq4f/posife.pdf
    • http://agarimo.com/archivos/archivos/45966966236.pdf
    • https://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fcb45a284f---45052815262.pdf
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079ff0fa81d1---42890611783.pdf
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/mtirlddv70jige1m7c3o1ak8gt/zujuxomuwudekogeka.pdf
    • https://arizonalightingsales.com/wp-content/plugins/super-forms/uploads/php/files/cc1ee1fa6aa2e19e12a181b155be6821/dovuku.pdf
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/b4a86c096ffb44d72988110a66dfb7b6/60260660957.pdf
    • http://adamlegal.com/userfiles/file/38802708163.pdf
    • https://freedomtampons.com/wp-content/plugins/super-forms/uploads/php/files/24f450504d9ed227f37f0656db7cc683/43053659516.pdf
    • http://nctpa.biz/clients/5/51/51e593b678cc4707ea5ff7b662bcbdb9/File/rufisuvowod.pdf
    • https://penal-garazh.ru/files/95599053212.pdf
    • https://medok18.ru/wp-content/plugins/super-forms/uploads/php/files/14ebbf83d2f28f7269a679442615c137/39890701877.pdf
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/ee34b4590b6c5d10e7b819418e55e195/duparinilulabisojuga.pdf
    • http://iideree.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606d8b140165d---xepuporukififuviraforonuf.pdf
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16092e1e650964---98567310776.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_off0000d80a.bin
97399f33c3850e04b810536305fd11aa1d2863bc0f6aff8385235e7d28830607
pdf-font-stream PDF embedded font (sfnt) at offset 0xD80A 17656 bytes
font_01_sfnt_off0001064d.bin
02c0121b75dfd4b5811ceda9399a34bd234ddead5a217abc695c76231417b081
pdf-font-stream PDF embedded font (sfnt) at offset 0x1064D 10560 bytes
font_02_sfnt_off00011e4d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11E4D 16792 bytes