Malicious PDF — malware analysis report

Static analysis result for SHA-256 a43cf33a81c571e1…

MALICIOUS

PDF

91.0 KB Created: 2021-07-21 15:55:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 07d530f1327c4c24891d45f107e2cab2 SHA-1: 7d892d1f281829021d89d139b02196e1a3213531 SHA-256: a43cf33a81c571e1d0eec23399baede1ea641ef1117c543bbbfe42f0b759e9c2
156 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS uploads. The presence of numerous unknown URLs suggests a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://yourlightingbrand.com/wp-content/plugins/super-forms/uploads/php/files/eff1de39851993e3e48f95ff7b177c70/70268368444.pdf In PDF document text
    • http://brette-animation.com/userfiles/file/mazubuvijadogin.pdfIn PDF document text
    • http://stepsforstarlight.org/clients/c/c6/c668404594a1c08d975ab50c7bec58f6/File/kevisorobivizepasivev.pdfIn PDF document text
    • http://csc-028.com/userfiles/file/20210707064447_iscwz7.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/l33atdcr89480i5ab6sgsen9sd/selufuk.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/bc7824b2559ea301e016397b5280a495/nozojux.pdfIn PDF document text
    • http://randoquad72.fr/userfiles/file/mojovivawememasube.pdfIn PDF document text
    • http://gayaarchi.com/userfiles/file/20210520115440.pdfIn PDF document text
    • http://bigandtallking.com/userfiles/file/zadedorisemubabotobete.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093129e75c46---23318535983.pdfIn PDF document text
    • http://radio-salsa.com/php/rs/filesupload/file/29946705439.pdfIn PDF document text
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16090eef3517e5---37675597933.pdfIn PDF document text
    • https://thehamptonsbloomington.com/wp-content/plugins/formcraft/file-upload/server/content/files/160760d5c8c88e---walevebizawuk.pdfIn PDF document text
    • https://fiambreszav.com/wp-content/plugins/super-forms/uploads/php/files/65015bbfb619393f72e8ed66f18caddc/lemagejeruxopetamepaxodig.pdfIn PDF document text
    • https://contabil-fiscal.ro/mm/file/92113004853.pdfIn PDF document text
    • http://topnotchimports.com/ckfinder/userfiles/files/85131335276.pdfIn PDF document text
    • http://centralgiving.com/media/userfiles/file/66712797237.pdfIn PDF document text
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/160830382779cb---pewoz.pdfIn PDF document text
    • http://miyozenemeryville.com/uploads/files/tuxigitijes.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160f25b264a669---47403217395.pdfIn PDF document text
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/cd0du6chit4agc7ga7elb807rp/82854545855.pdfIn PDF document text
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607cc8b8e94e7---57066440090.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160a94f0c2dc9d---45890919327.pdfIn PDF document text
    • https://wendi101.com/userfiles/file/ninajetajinazata.pdfIn PDF document text
    • https://isosklo.cz./uploads/rusupazu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=how+to+get+blood+out+of+grey+sweatpantsPDF 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_off0000ff5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF5F 11012 bytes
SHA-256: 0864f803245c6257c32e86625af341d8d1be4467058589796e241bb861adad32
font_01_sfnt_off000118bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118BD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000130cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x130CF 17292 bytes
SHA-256: 030cca55f0b28d06742ea0e720e79f0ef7537b6d123bdc09cdf3256fae6ded06