Malicious PDF — malware analysis report

Static analysis result for SHA-256 fcf8fc9515bc79e2…

MALICIOUS

PDF

73.3 KB Created: 2021-07-12 17:33:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4b27e911ee73bb6634315368bd08ae40 SHA-1: eb48f9213288659e007f66c11d1eaa826a2877e0 SHA-256: fcf8fc9515bc79e228aac477a9485d234e975f468f412f0cbc9eb3b9b6902d59
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised WordPress sites, suggesting a phishing or malware distribution campaign. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, lacking readable content but containing embedded artifacts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://cructi.ru/uplcv?utm_term=given+two+sides+of+a+triangle+find+a+range+of+possible+lengths+for+the+third+side
    • http://streathamtaxi.com/survey/userfiles/files/42883063453.pdf
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/lo78oqg2f02lhrqe2ko410nhak/sewitigodenokawu.pdf
    • https://airbays.com/userfiles/file/tidofepafolinemez.pdf
    • https://amagi.la/wp-content/plugins/formcraft/file-upload/server/content/files/1609cc7d19da32---xuwefowuro.pdf
    • http://sshs61.com/clients/6/60/60e739d5a8cf4a6710e4f064fd99417d/File/vanutazazatesamelukibak.pdf
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16072c8caa3719---daxegasuniviz.pdf
    • http://abwplazaview.com/uploads/files/41356560125.pdf
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bf8b78b27b4---veradutawab.pdf
    • https://feriaesotericadeatocha.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b53c33ea29---viloxosi.pdf
    • https://accuratesearch.com/userfiles/file/suwalilaxidosutofomuwab.pdf
    • https://voicelux.ru/wp-content/plugins/super-forms/uploads/php/files/f53ef095e5cbabb38dedff294f78b853/rawunaset.pdf
    • http://ranjitabiswas.com/userfiles/files/wafamifur.pdf
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1608ce100b8810---69405171077.pdf
    • https://cashmeredreams.com/wp-content/plugins/super-forms/uploads/php/files/4767a78c893b20f6de7e1e9481c1288f/45173248566.pdf
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/160805d9375d95---34972890476.pdf
    • http://stauarchitetti.eu/userfiles/files/xebumodoxikaxitojimufeje.pdf
    • http://galluccifaibano.com/userfiles/file/dojojolitifiniworozezu.pdf
    • https://fnb-concepts.com/images/uploads/files/90813652934.pdf
    • https://autotrilogy.com/wp-content/plugins/super-forms/uploads/php/files/8757721b7ca56ae51a15eb1a6fa2156f/xulajog.pdf
    • http://www.rlktechniek.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16087c38612238---69814604386.pdf
    • http://aptchasers.com/FCKeditor/userfiles/file/tarufonojekapatuwu.pdf
    • https://www.kngroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c7b2c08eaa---20327647417.pdf
    • https://qualitycountscleaning.com/wp-content/plugins/super-forms/uploads/php/files/808eb7f1227f38a3a7c38293606928f4/podimagativuzef.pdf
    • http://qlinairnv.be/userfiles/file/pisorelure.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_off0000ba77.bin
aafa38eed95a0349b1cdc3ca23ced83bfd803e4ad82f7e81d15900a32b3b0ab5
pdf-font-stream PDF embedded font (sfnt) at offset 0xBA77 11108 bytes
font_01_sfnt_off0000d3f6.bin
b212e42835e6a779968fb68ef35177211be10017ed58e2735498fa7a65347292
pdf-font-stream PDF embedded font (sfnt) at offset 0xD3F6 16516 bytes
font_02_sfnt_off0000ff21.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFF21 16792 bytes