Malicious PDF — malware analysis report

Static analysis result for SHA-256 749f7a7661d39122…

MALICIOUS

PDF

70.5 KB Created: 2021-09-11 01:54:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 3f30076c4772521a8e08f79d58cdb531 SHA-1: 0b8e4fe021f3491fdcf5a25a7c0c1bdf2cf7a49f SHA-256: 749f7a7661d3912206650990d48a942a333a84eb77e8f6013354f77747354250
96 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

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 https://nomylo.ru/uplcv?utm_term=smart+fit+app+apk PDF link annotation
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161368cc99bbf2---zuzizavanapowogodezak.pdfIn PDF document text
    • http://ersatzmonitor.de/userfiles/file/94500128606.pdfIn PDF document text
    • http://letsfinal.com/userfiles/file/66477832163.pdfIn PDF document text
    • http://yibetter.com/data/files/joxifebikumupubugig.pdfIn PDF document text
    • http://prtourusa.com/FileData/ckfinder/files/20210909_69622BA7B7F44EF7.pdfIn PDF document text
    • http://k9careclinic.in/ckeditor/ckfinder/userfiles/files/24060326044.pdfIn PDF document text
    • http://scales-center.com/shop/fck_file/file/87822226051.pdfIn PDF document text
    • http://villahetzwartepaard.nl/survey/userfiles/files/38636119504.pdfIn PDF document text
    • http://uralteplostroy.ru/content/file/kixusifewin.pdfIn PDF document text
    • http://asesoriazabalburu.org/azaba/files/file/78893761547.pdfIn PDF document text
    • http://rsti.biz/files/fck/file/sisozasijufurizabife.pdfIn PDF document text
    • http://artkulinaria.pl/sites/default/files/file/mapizerijalovumimuv.pdfIn PDF document text
    • http://3sdent.com/upload/files/24311883021.pdfIn PDF document text
    • https://ce-mi.pl/uploads/userfiles/files/33552618304.pdfIn PDF document text
    • http://lienming-rubber.com/uploads/files/202109011424314597.pdfIn PDF document text
    • http://ersenergy.com/UserFiles/file/8409226728.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/161312fe7494c8---sapenap.pdfIn PDF document text
    • http://himalayakebab.irafbrothers.com/shipinc/userfiles/files/wulorij.pdfIn PDF document text
    • http://streathamtaxi.com/survey/userfiles/files/10614333715.pdfIn PDF document text
    • http://emailreceptionist.net/userfiles/file/mitudasu.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f9baa4d848---43811911926.pdfIn PDF document text
    • http://imssp.by/data/images/fxeditor/file/kegigukikojaraj.pdfIn PDF document text
    • http://tjsijiqing.com/ckfinder/userfiles/files/2021/0904/45037969ef30cff1aa49ebf3fa49e3f0.pdfIn PDF document text
    • 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b622.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB622 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ce34.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE34 15572 bytes
SHA-256: 4620e9e9767e45be90b6bc2dd7b23af1f1e12a16b67cd11cbb954c96d6a6f493
font_02_sfnt_off0000f5ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5EE 10116 bytes
SHA-256: 752f58e70d508d297c4012d4ede56f76e98807532838b585cbc4a182fa84feab