Malicious PDF — malware analysis report

Static analysis result for SHA-256 1f99bfc7a2917388…

MALICIOUS

PDF

71.0 KB Created: 2021-09-23 16:58:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: b16e9438ba15829c11214aea360c70da SHA-1: ebc66172d7d7ebfec22f93e54ad21a57bbd9e935 SHA-256: 1f99bfc7a2917388e6ac02f43b132475ceef61669bbb0c50e10c66ea91681581
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, forming a link farm. These links likely serve to redirect users to phishing sites or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://coretry.ru/uplcv?utm_term=vegas+criminal+simulator+mod+apk PDF link annotation
    • https://wwa.bdbabymart.com/app/webroot/ckfinder/userfiles/files/tiveve.pdfIn PDF document text
    • https://onderhoudnlgarantie.nl/upload/file/kogabamamas.pdfIn PDF document text
    • https://autosofortkauf.ch/wp-content/plugins/super-forms/uploads/php/files/d1uspacaimrg1hl61rnq8v9p05/xijigufatuxifajado.pdfIn PDF document text
    • http://hndgyl.com/v15/Upload/file/2021932055461003.pdfIn PDF document text
    • https://khmernative-rice.com/userfiles/file/lilotoz.pdfIn PDF document text
    • http://clerus.hu/files/file/57913973394.pdfIn PDF document text
    • http://beverly.kopanramen.com/uploads/files/94567472811.pdfIn PDF document text
    • http://sakesushilakehavasu.com/uploads/files/pajojexonuxufetivoxeji.pdfIn PDF document text
    • http://orthodoxnews.us/file/89091172182.pdfIn PDF document text
    • http://tuzvedo.hu/elemek/file/33375856571.pdfIn PDF document text
    • https://fleschimmo.lu/userfiles/files/31350652775.pdfIn PDF document text
    • http://xn--9w3b270a7kf.kr/ckfinder/userfiles/files/lemowevodoganusuno.pdfIn PDF document text
    • http://bmcnx.com/userfiles/file/1276636820.pdfIn PDF document text
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/161349f7dedf58---mirefenupifejikupomumi.pdfIn PDF document text
    • http://yushendesign.com/images_fck/file/1631539888.pdfIn PDF document text
    • https://marathonroller.com/userfiles/files/numetozepexulefoxozeworu.pdfIn PDF document text
    • https://twinslock.com/ckfinder/userfiles/files/45662425916.pdfIn PDF document text
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/8f36f51ce6e811662782eedbdffcb71b/95446423684.pdfIn PDF document text
    • https://smartstone.ca/userfiles/files/49919878643.pdfIn PDF document text
    • https://anna-bel.com/app/webroot/files/userfiles/files/gotivimulogogasurabozafer.pdfIn PDF document text
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613595d5cb7a8---bedekikinapawe.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_off0000b28d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB28D 11016 bytes
SHA-256: 140896282b02d5d5d9b4ebd23446ed3020c7f08fd35afad5123edb46d0708bca
font_01_sfnt_off0000cbf9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBF9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e40b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE40B 16580 bytes
SHA-256: 5eb182e629972356e937734a4c68783c5b3a2cb23f5648a738785beb493cfb97