Malicious PDF — malware analysis report

Static analysis result for SHA-256 d18b837d92d649c8…

MALICIOUS

PDF

71.4 KB Created: 2021-09-23 11:01:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: a48b108bcfa9759b7356c42887917149 SHA-1: 87bfb3975d54659f7b15d24ee70fced45b30e444 SHA-256: d18b837d92d649c84b520f108fa7d1b2d8e46da3e93aa74bb1d8e5b96c65dfaf
156 Risk Score

Malware Insights

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

The PDF document was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to lure users to malicious content. The presence of multiple link farm heuristics further supports this assessment.

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 http://alrabbancapital.com/file/files/latojinumemasarotidabaju.pdf In PDF document text
    • https://badeluxe.com/userfiles/files/59345750447.pdfIn PDF document text
    • https://www.mmgrowersg.com/ckfinder/userfiles/files/pavoxiveragofofafi.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/a3m51bno2fqs7jtenk0k16hi5u/45547316917.pdfIn PDF document text
    • https://bor-diing.com/upload/files/15205284291.pdfIn PDF document text
    • https://www.shopveriamici.com/wp-content/plugins/super-forms/uploads/php/files/upfi4b5820brmracatu5uk93ug/debini.pdfIn PDF document text
    • http://rockycheng.com/ckfinder/userfiles/files/pesorop.pdfIn PDF document text
    • https://pima-alarms.net/slicice/file/80801466549.pdfIn PDF document text
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613276005d752---76073595669.pdfIn PDF document text
    • http://www.reeder.ee/files/filemanager/33690398034.pdfIn PDF document text
    • http://cambridgekapurthala.com/damana/userfiles/file/mojuwokagomuna.pdfIn PDF document text
    • https://flour.co.uk/ckfinder/userfiles/files/gibewusifelexojujon.pdfIn PDF document text
    • https://equinox-e.com/upload/UserFiles/file/raluwenetobuxifudid.pdfIn PDF document text
    • https://marblobaths.ph/app/webroot/img/files/fetibi.pdfIn PDF document text
    • http://shrlie.com/upload_fck/file/2021-9-12/20210912171816606442.pdfIn PDF document text
    • http://www.amanuttarakhand.org/ckfinder/userfiles/files/regowigoninuluzemad.pdfIn PDF document text
    • https://ateneoarbonaida.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b60ea8fc73---59635864032.pdfIn PDF document text
    • https://xn--80adj7cxa.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/042c7213105f25f773dbace8965451b2/lezoxakobiwinubipokoso.pdfIn PDF document text
    • http://hoachattn.com/image/files/41154402779.pdfIn PDF document text
    • http://hajnysport.cz/FCK_userfiles/file/pepawagoduzurirepukuwevot.pdfIn PDF document text
    • https://travellifeafrica.com/ci/userfiles/files/56592578589.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=where+can+i+watch+emma+2020PDF 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_off0000b405.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB405 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cc17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC17 17220 bytes
SHA-256: a67c0b8960cf6186925c3f6cc0b8d02f3b38a8e2178be081301c95454fa0434a
font_02_sfnt_off0000f899.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF899 10480 bytes
SHA-256: b1221057576069de9a4c47ed28da60fad1ea7ff5c60c5d29b131ba274e406056