Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4eff4b1b4fa2309…

MALICIOUS

PDF

74.6 KB Created: 2021-06-19 13:56:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: deff9a72ee7ea604a2f580169b69b732 SHA-1: 9a41c1bd6cadc5739153d779820e573b6df89b4f SHA-256: b4eff4b1b4fa2309ab46969c6cf062b823c9602024e329b32d7d8b2c03fc0b1d
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to various websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, and the document body was unreadable.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://anhuizhkj.com/upload_fck/file/2021-5-25/20210525234433401320.pdf In PDF document text
    • https://rhdplumbing.com/wp-content/plugins/super-forms/uploads/php/files/a6ca62d61ff8850e4777ecd178160aae/38369206584.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160722bb5f3c9e---88009200052.pdfIn PDF document text
    • http://iseveranscopy.com/upload/editor/file/74454569831.pdfIn PDF document text
    • https://balustrady-metalik.pl/files/xevev.pdfIn PDF document text
    • https://youstore21.com/wp-content/plugins/super-forms/uploads/php/files/41207f57937ed46521a6b362dd19a2ef/pejozemupobefijivuvilifat.pdfIn PDF document text
    • https://catherinehourihan.art/wp-content/plugins/super-forms/uploads/php/files/08ea495fd99ff3fb7e5e69994863633f/topasopisibase.pdfIn PDF document text
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d8aa2219c9---13401969529.pdfIn PDF document text
    • http://cedule-plachty.cz/files/file/3913279947.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5fae3c69f4---xanoka.pdfIn PDF document text
    • http://www.thediethub.in/wp-content/plugins/formcraft/file-upload/server/content/files/1607685080fc4b---78061064716.pdfIn PDF document text
    • http://www.stallionreadymix.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16087f7237a4ea---45040049724.pdfIn PDF document text
    • https://inncredel.com/uploads/64212537756.pdfIn PDF document text
    • http://amy-tsai.com/images_express/userfiles/files/83270257683.pdfIn PDF document text
    • http://southfieldhigh1973.com/clients/2/27/27a5067865c8334ad4a5a1fd7642c928/File/miresozakironogoxunili.pdfIn PDF document text
    • https://uppersanduskyrotary.com/cms/files/File/52801743849.pdfIn PDF document text
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160948bfce9568---jerogolurojegekuw.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=fake+caller+id+mod+apkPDF link annotation
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dca1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCA1 5060 bytes
SHA-256: 8196d4a8c8330ed56e341c433a58080aa756dd98ae2c87ef9c47dc7aa76407e5
font_01_sfnt_off0000edbf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDBF 1800 bytes
SHA-256: e9a5a1f6ed95b1e3669933bb00002ad32a1708c3e0b735191cad5e02368a6c7d
font_02_sfnt_off0000f64d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF64D 11344 bytes
SHA-256: 859fef4847b674e298d7a1582ae59c8acd739a53e211a60ad9adce9fa3019f35