Malicious PDF — malware analysis report

Static analysis result for SHA-256 916f3a56968de115…

MALICIOUS

PDF

81.5 KB Created: 2021-09-10 14:24:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b89aca07cfbc3b65a39bb33ad65d2e4c SHA-1: 65fd37fa14bc00adc7cf6fad5d2f58c5b0377f4e SHA-256: 916f3a56968de1153aef353bff7121aaa9d81516da59c3299c988d57fe4cbadc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded links, many pointing to compromised WordPress sites and disposable hosting, suggesting a link farm for phishing or malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded links are indicative of malicious activity, likely related to initial access via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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 http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130ebfda7cda---82687701620.pdf
    • http://polishingmarblefloor.it/userfiles/files/2065940279.pdf
    • https://lockerova.eu/admin/upload/documents/kuzibo.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161370195efc59---wowidijoliwobizosebat.pdf
    • http://thermogroup.ru/uploads/files/89946637323.pdf
    • http://hamkr.com/userData/board/file/rupijo.pdf
    • https://duvarkagidierzincan.com/userfiles/file/57107429513.pdf
    • http://www.ambatownship.com/ckfinder/userfiles/files/sigapuvuxo.pdf
    • http://agapetown.net/ckfinder/userfiles/files/48137931093.pdf
    • https://sunkamalzemecilik.com/userfiles/file/70267239101.pdf
    • http://caffepontoni.com/uploads/file/4273910979.pdf
    • http://greathorserider.com/ckfinder/userfiles/files/rerijofikupiwuwasiw.pdf
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/3be3e1c49cb83fb8250fdb5d8eb22e68/64605676593.pdf
    • https://lifeteacher.tw/uploads/files/202109010314533854.pdf
    • https://nirmalujjwal.com/public/ckfinder/userfiles/files/gutinepelej.pdf
    • http://pushgroup.lv/userfiles/files/88117389849.pdf
    • http://1-cities.com/blog_images/blog_/file/tenofuwopitiwa.pdf
    • http://rurisnet.org/images/file/tekesolexijubi.pdf
    • http://pibar.tw/uploads/files/202109051056489932.pdf
    • http://palestraarkadia.it/userfiles/files/taxujalosenewalom.pdf
    • http://dijladentalcenter-qa.com/userfiles/file/sutiselod.pdf
    • http://pactolous.hu/upload/file/reneragidodinotukodidazi.pdf
    • http://www.hypnotiseur.com/wp-content/plugins/formcraft/file-upload/server/content/files/161340a764acc5---juvazup.pdf
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613aedbf4d6ae---motaxavafeguxasokexev.pdf
    • http://aaz.sk/editor_uploads/files/2563886895.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=real+football+2019+download
    • 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_off0000daad.bin
0905ce441544f8b5a70e083b2286249aa36b8ed8b053a857e191abe6f0fd716f
pdf-font-stream PDF embedded font (sfnt) at offset 0xDAAD 10720 bytes
font_01_sfnt_off0000f38c.bin
e73ebaaddb2199230be39341c4570f2504aa112ad3d078012660c7b2bb2d2c8d
pdf-font-stream PDF embedded font (sfnt) at offset 0xF38C 17232 bytes
font_02_sfnt_off0001207d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1207D 16792 bytes