Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8af645a784814c1…

MALICIOUS

PDF

89.0 KB Created: 2021-07-26 23:47:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 1cbea69b9c6f16e187afca0a8ecc7aa9 SHA-1: 391fbd2b0d33fda78b44a97a1990a1d4fe959d30 SHA-256: a8af645a784814c1a0d333b7911e8608f5f9c192ba9de89e564a10b353a5c49c
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous compromised WordPress sites, indicating a likely SEO poisoning or phishing campaign. The ML classifier strongly flagged this PDF as malicious. While no scripts were directly extracted, the structure and embedded URLs suggest exploitation for client execution, potentially via a malicious link that could download a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://www.tangelo.no/wp-content/plugins/formcraft/file-upload/server/content/files/1608aa8bc23504---wasewatoletokutipu.pdf In PDF document text
    • http://banglatalkies.com/dynamic-images/cms/file/nenok.pdfIn PDF document text
    • http://scmsalliance.com/clients/864514/File/xigakijuwuzi.pdfIn PDF document text
    • https://summit-christian-academy.net/scauserfiles/files/93533690089.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/plk070eulhqvf4ufp0dp2d4f23/busulalozujiwewokonewod.pdfIn PDF document text
    • http://pphu-joanna.pl/fckpliki/file/94053845899.pdfIn PDF document text
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/4e04a72cf449b8e08a0ffb711a0e037f/96445784080.pdfIn PDF document text
    • https://muguet.fr/sites/default/files/file/11980474087.pdfIn PDF document text
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608ad7b42fb37---pogivoji.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076fd3b3ce66---jiguzakavoziwawixu.pdfIn PDF document text
    • https://srmhospitalities.com/images/bulk_images/files/31680352946.pdfIn PDF document text
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b5b5f37a4c---kifarigirevojinejibewije.pdfIn PDF document text
    • https://whitelightdesign.com/wp-content/plugins/super-forms/uploads/php/files/b48c4471b6ba732ae576cce1e38a604a/varuxevudezudagenumu.pdfIn PDF document text
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160d51c2b48c36---47894315388.pdfIn PDF document text
    • https://www.dars.bg/ckfinder/userfiles/files/33045114832.pdfIn PDF document text
    • http://unipsyclinic.com/userfiles/file/20210723224620.pdfIn PDF document text
    • https://balticstroy.com/uploads/files/93312344036.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ff1420b0ede---tinevavosofiwup.pdfIn PDF document text
    • https://korovin.org/site/img_ufiles/puvimonedigepevovufumitu.pdfIn PDF document text
    • https://mikepromedia.com/wp-content/plugins/super-forms/uploads/php/files/i27i48icermlcknvd67ude2eq4/xawozujatawinad.pdfIn PDF document text
    • https://fertilizerproductionprocess.com/d/files/gosoxuneturexobe.pdfIn PDF document text
    • https://www.simcoerecovery.net/wp-content/plugins/super-forms/uploads/php/files/195qtitfg4462esltmk8hk9jks/33639293255.pdfIn PDF document text
    • https://horkolas-gatlas.hu/ufiles/file/junimenogetixogutilorad.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/1608971759420e---kaluzeremenawujo.pdfIn PDF document text
    • http://studioaba.net/userfiles/files/65301421619.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=why+is+my+remote+power+button+not+workingPDF 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://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_off0000f96b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF96B 16828 bytes
SHA-256: 49a258cd108deec53f8ee77f8896c18473ea8015bf77b5574bbf3c39d10f8454
font_01_sfnt_off00012553.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12553 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013d6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D6A 11016 bytes
SHA-256: cdcaf24ad1ad106ca134dd959ad75408d46b8600c29b97e1e60fc636316d7827