Malicious PDF — malware analysis report

Static analysis result for SHA-256 638ff94adc3ac166…

MALICIOUS

PDF

73.7 KB Created: 2021-06-29 16:10:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: edcede5a77d5494622562ff99ad7beae SHA-1: ffe94bef743e0754a002f6eafff3a2933ecac4fd SHA-256: 638ff94adc3ac1667888c5d33d247ca32ab5e1397654b3ba75859f53bedd7249
156 Risk Score

Malware Insights

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

The PDF document contains a link farm pointing to multiple compromised WordPress sites, likely intended to lure users into downloading malicious files. The ML classifier and ClamAV detection strongly indicate malicious intent, with the document acting as a distribution vector for further compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://higher-reason.com/wp-content/plugins/super-forms/uploads/php/files/fqf6haqs9uh1c1kp5i06p9hho1/95520147511.pdf
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608dc0c122648---45027727970.pdf
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c95fcf19d56---buxapunusaduziw.pdf
    • https://www.drmarlenebothma.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160ac4ef262673---71957039799.pdf
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1608ff26cc3503---nakototalijexobo.pdf
    • https://afanasyev-design.ru/wp-content/plugins/super-forms/uploads/php/files/e9416f0dc643c8f35e80dbbb36b5c0d4/19688523897.pdf
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/e5fcac450a6e134b8ba65b2ebb865abe/pelinalanozav.pdf
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbff878b871---45196923161.pdf
    • https://sitebyside.ru/wp-content/plugins/super-forms/uploads/php/files/8eed6e6aa7a372098414debbe1301e90/92159761174.pdf
    • http://sage-chem.com/image/files/20210606_034537.pdf
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160767c429cc4d---8927572135.pdf
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b059d817aec---xufenezapogogutap.pdf
    • https://waroproject.com/file/tiwoditumeluximon.pdf
    • https://www.kunapak.com/wp-content/plugins/super-forms/uploads/php/files/gb4c9oh6h12hjfdrv150do9gqg/75674404099.pdf
    • http://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/16075eeefe2e49---45441558072.pdf
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c52bc360ff1---gidorusoliwos.pdf
    • http://maybomchuachay24h.com/Images_upload/files/22081288479.pdf
    • http://arohitourandtravels.com/userfiles/file/ridafix.pdf
    • http://alumcity.ru/userfiles/file/pefokoxajemoritavazapeb.pdf
    • https://www.breastcancerfoundation.in/wp-content/plugins/super-forms/uploads/php/files/1e5ef5d17e4a3288ffa3c23676fbf196/jogopuwutemenototiti.pdf
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/teohr22ivo3cnii9rbuhekqdnj/piboxikunog.pdf
    • http://pivotal-technologies.com/userfiles/file/wexirijofenixukadigizu.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=meaning+of+small
    • 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_off0000c13b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC13B 16792 bytes
font_01_sfnt_off0000d952.bin
9495432b632d0d373072661f2a62afbe10a03d610d5e3fb7829bd3b7613101ee
pdf-font-stream PDF embedded font (sfnt) at offset 0xD952 10352 bytes
font_02_sfnt_off0000f0a0.bin
db9606a35ca6d2166cf125d23a2ea7b40877f16a736ee8190ee61c1210bdf27d
pdf-font-stream PDF embedded font (sfnt) at offset 0xF0A0 16160 bytes