Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a23bf0ef9a2d536…

MALICIOUS

PDF

85.5 KB Created: 2021-09-18 09:49:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 5e4312f0ca413c370898073f94444299 SHA-1: e39728a82dd0d3ac3d9e053893c2a24cf41e033e SHA-256: 5a23bf0ef9a2d536d0c7378bb427b8238b2e1bd9639754fdc93a367f5174f358
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links pointing to various domains, many of which are hosted on compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The presence of multiple external URIs and link farm heuristics strongly suggests an attempt to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 http://dytac.hk/userfiles/72459086091.pdf In PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f41c040b92---wulezofixoxuzifo.pdfIn PDF document text
    • http://instant-image.net/UserFiles/Site/File/gipome.pdfIn PDF document text
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16133c1ff12a98---67989044653.pdfIn PDF document text
    • http://yotlist.com/uniformkontakt/userfiles/image/files/88126372780.pdfIn PDF document text
    • http://deborahkay.com/ckfinder/userfiles/files/9035423783.pdfIn PDF document text
    • http://bukharaatlanta.com/sites/default/files/file/xevawoxidikumidupalefi.pdfIn PDF document text
    • https://mldom.xyz/web/img/podborky/files/xumenubowejifijined.pdfIn PDF document text
    • http://cu-hinothai.com/ckfinder/userfiles/files/pafuvivune.pdfIn PDF document text
    • http://orderkai.com/uploads/files/gewabamibepubugum.pdfIn PDF document text
    • http://studiopedrazzini.eu/userfiles/files/96863455027.pdfIn PDF document text
    • https://hijaulumut.com/contents/files/20633511567.pdfIn PDF document text
    • https://alkoplast.rs/files/61365812681.pdfIn PDF document text
    • https://gamedunyasi.com/calisma2/files/uploads/14259383972.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143a4868451a---53327752724.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1614192b921141---3377730090.pdfIn PDF document text
    • http://nissanotogovap.net/uploads/images/files/lebiladigalifipa.pdfIn PDF document text
    • http://dangkykinhdoanhkiengiang.com/upload/ck/files/tarafawijebejupofus.pdfIn PDF document text
    • http://philboyd.com/vivudiziji.pdfIn PDF document text
    • http://texinpack.com/uploadfile/file///2021091216524870.pdfIn PDF document text
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130a6afcb1db---91768965557.pdfIn PDF document text
    • https://x-software.cz/data/file/kamotasuku.pdfIn PDF document text
    • https://grandplaza.bg/uploads/assets/file/kumewil.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=how+to+get+free+android+gamesPDF 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_off0000ea0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA0C 10728 bytes
SHA-256: 6a1f59fef297ccd00b26a49e1497a3092f6f3a62e406ca3e3d02aa33df164b83
font_01_sfnt_off00010283.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10283 17740 bytes
SHA-256: 0035f98db096d19af68e8965259e852340784f800655e55f9cffad5fbad338cb
font_02_sfnt_off00013068.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13068 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1