Malicious PDF — malware analysis report

Static analysis result for SHA-256 81b21712312f3bbb…

MALICIOUS

PDF

82.8 KB Created: 2021-07-07 00:56:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c7cd08bcdd1ec0675738273c4457a4fe SHA-1: adf031e6c70fe62e7869070f197a4eebb8010da8 SHA-256: 81b21712312f3bbb418d93c175537c32b7b9784af2e389c9af18bd2989fc77fd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised websites, suggesting it's part of a phishing or malware distribution campaign. The PDF structure and embedded links are consistent with techniques used to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://archism.ru/uplcv?utm_term=bison+coffee+house
    • http://www.luminicaambiental.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098564e7d79a---voduxerikefubijuvulivid.pdf
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/ca732a679b26dcbd94c85218af827ea9/vererijalujagexuvajof.pdf
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c5c6b320de1---90658146530.pdf
    • https://leosservices.com/userfiles/file/mixalexomote.pdf
    • http://gf-location.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160ac37254d0c8---16060786494.pdf
    • http://campfirewtx.org/userfiles/file/95152294610.pdf
    • http://worthingtonpark101.com/userimages/luvukusivaxaxubukivapa.pdf
    • https://nailseasupportgroup.com/wp-content/plugins/super-forms/uploads/php/files/8a6fd7b0e4b89565c648c6b21d27ca83/87566617372.pdf
    • https://comesa.com.pe/wp-content/plugins/super-forms/uploads/php/files/7cju2bsvvf9ev05jk9d29gomg1/62024478966.pdf
    • https://aviseco.ro/userfiles/file/jababivosinosifokelatirol.pdf
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/16093e7b4bc877---gofalupejoperetixexekoteg.pdf
    • https://nhanloc.net/userfiles/file/jijeka.pdf
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e8eea97026---fufofizokusidegemime.pdf
    • https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/3d845a4576b93a589cb634c916985666/rafobififub.pdf
    • http://residencecarlofelice.com/userfiles/files/14221280195.pdf
    • http://vasvaripalmuzeum.hu/upload/file/boxedawutaligaxak.pdf
    • https://esteticarcare.com/wp-content/plugins/super-forms/uploads/php/files/abf7614e3addab68fe7ae7df2f50790d/rixutax.pdf
    • http://sacoorhealth.pt/site/upload/file/kefavikanofojazagaj.pdf
    • http://msci.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/160dbc23dba97b---85611114112.pdf
    • http://ombs.ru/uploads/files/saludakobul.pdf
    • http://nprofit.hk/userfiles/zunalidam.pdf
    • http://lisaarkin.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/73567240096.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_off0000e2a2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE2A2 16792 bytes
font_01_sfnt_off0000fab9.bin
577d5a737d0406623fb50dcbcc38494aef8674e7a665f2e2cfcf73ca84fd408f
pdf-font-stream PDF embedded font (sfnt) at offset 0xFAB9 10180 bytes
font_02_sfnt_off00011177.bin
f438ec3c79576c8121982b85940da7aa87929f3a42a98096d9d9dbfb3d8fc3d5
pdf-font-stream PDF embedded font (sfnt) at offset 0x11177 17372 bytes