Malicious PDF — malware analysis report

Static analysis result for SHA-256 6f6555b8b7afb871…

MALICIOUS

PDF

78.6 KB Created: 2021-09-19 10:36:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: e9a885d5b78b6fe60dca5b724bd58a62 SHA-1: 32fb0c0b2713c4ec3741015aff6955c9dc2ed922 SHA-256: 6f6555b8b7afb871e833774fc57117c27e2ff220c4ef09ecc87d8567a017daab
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external links, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to lead users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. No scripts were extracted, but the PDF structure itself is used to host the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://crysiq.ru/uplcv?utm_term=parallel+space+apk+for+android PDF link annotation
    • https://griby.biz/ckfinder/userfiles/files/buzawimisisase.pdfIn PDF document text
    • http://comicpapyrus.com/wp-content/plugins/super-forms/uploads/php/files/1148590f05ea11e2d7bdb4fc8d727c4b/76174007701.pdfIn PDF document text
    • http://aan.kz/ckfinder/userfiles/files/wobukonosoxiwivowilo.pdfIn PDF document text
    • http://28777886.com/Lpf/UPFILE/userfiles/files/8955705007.pdfIn PDF document text
    • http://hndgyl.com/v15/Upload/file/2021941031311480.pdfIn PDF document text
    • http://alconsprom.ru/ckfinder/userfiles/files/95067734912.pdfIn PDF document text
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f600919d9b---10916971248.pdfIn PDF document text
    • http://www.psychophonie-tarbes.com/ckfinder/userfiles/files/98761763350.pdfIn PDF document text
    • https://ccichn.vn/data/upload/file/biboduloforijigegewojijam.pdfIn PDF document text
    • https://beldapromosyon.com/calisma2/files/uploads/vifemadabezorefiviw.pdfIn PDF document text
    • http://originalavto.ru/userfiles/file/fasonemezilu.pdfIn PDF document text
    • https://snqrsl.quebec/upload/editor/file/dimered.pdfIn PDF document text
    • http://sunrui-ti.com/d/files/42242584833.pdfIn PDF document text
    • https://daquin-ferriere.fr/userfiles/file/9686435724.pdfIn PDF document text
    • http://fongyoskert.hu/userfiles/files/27447630351.pdfIn PDF document text
    • http://www.polni.si/Images/files/28665637562.pdfIn PDF document text
    • http://etkindenetim.com/resimler/files/moxebavena.pdfIn PDF document text
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/1612f3d8969a49---90515378690.pdfIn PDF document text
    • https://sandp-engineering.com/ckfinder/userfiles/files/vajaxaxijasokikikogobemin.pdfIn PDF document text
    • http://baove24h.org/upload/files/48765325599.pdfIn PDF document text
    • https://find-domain.lazy-online-shop.com/app/webroot/userfiles/files/wimizu.pdfIn PDF document text
    • http://a-pro-peau.fr/userfiles/file/sebediviwezijugofevebaxej.pdfIn PDF document text
    • 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_off0000d1b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1B6 16588 bytes
SHA-256: 1febe6b0342096c75aa574291d91a66a1b78b7152d2ef1ead4b38124162a9f55
font_01_sfnt_off0000fc76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC76 10608 bytes
SHA-256: f459e82b15b53f3e931fd28a5e2aecfde695d35ffea0730c6be126fd7dc430bb
font_02_sfnt_off000114cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114CD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1