Malicious PDF — malware analysis report

Static analysis result for SHA-256 6b7d78b9ae3d1dcb…

MALICIOUS

PDF

74.8 KB Created: 2021-09-18 10:28:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 856ba7368e632ca476e5059b31a67863 SHA-1: 0cffccf177be70c85114899260f5639c09cf71b7 SHA-256: 6b7d78b9ae3d1dcb6c878f5c226df919e117e05c2764dc04317fc0a8b84662c2
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery through these links. No scripts were extracted, and the document body was unreadable, so the rationale is based on the URL analysis and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://daltan.hu/userfiles/file/48003861732.pdf
    • https://rossbeede.com/userfiles/file/bufugisepujunajeg.pdf
    • http://kurskodkb.ru/page_edit/_samples/userfiles/files/xokutep.pdf
    • http://amako-ra.com/wp-content/plugins/super-forms/uploads/php/files/4a4c692ca855b88a951b03c185892ba4/pirogadijidub.pdf
    • http://lnyuanzong.com/uploads/files/20210908204521.pdf
    • https://its-bulgaria.bg/files/file/73091719493.pdf
    • https://spotiverify.com/ci/userfiles/files/vigokipoji.pdf
    • http://austria-ex.com/images/blog/file/90692173864.pdf
    • http://bestforfishing.com/wp-content/plugins/super-forms/uploads/php/files/ca75abc4c1abb700db3399cf2ea4e8b3/72249495751.pdf
    • http://candientushinko.com/images/file/64201599432.pdf
    • https://www.limratechnologies.net/wp-content/plugins/formcraft/file-upload/server/content/files/16139ab3ba7ff0---rabipirunumixogemavijudet.pdf
    • http://porpora.group/imagenes/imagenes_contenidos///riwatunow.pdf
    • http://orthodoxvaidikasanghom.org/userfiles/file/wovoweruletizumiporu.pdf
    • https://datawire.gr/files/files/puridikiz.pdf
    • http://hotelpenza58.ru/ckfinder/userfiles/files/jafudusodokexelug.pdf
    • https://santehsevast.ru/userfiles/files/56251542393.pdf
    • http://ibb-online.ru/f/file/89884774336.pdf
    • http://ellev.fr/upload/files/betakinixumosi.pdf
    • https://sammycar.ch/sammy/sites/default/sammyfiles/newsletterfile/76831471693.pdf
    • http://emailreceptionist.net/userfiles/file/kefofamuxovozogo.pdf
    • https://dangeloremodeling.com/nbloom/fckuploads/file/45276265302.pdf
    • https://ariconium.cz/webpagebuilder/ckfinder/userfiles/files/konazimigokela.pdf
    • https://mayxaydunghoangphuc.com/userfiles/files/sovovim.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=system+tracing+apk
    • 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_off0000c1cb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC1CB 16792 bytes
font_01_sfnt_off0000d9dd.bin
6477b0b612c230c6861448f662038a24964c50a2a92eae87e6566eb0e1b48e25
pdf-font-stream PDF embedded font (sfnt) at offset 0xD9DD 16500 bytes
font_02_sfnt_off00010483.bin
a4c54fbd58dafaafcc440e7161d50fe74343469561fc7b082e6496ec3c303796
pdf-font-stream PDF embedded font (sfnt) at offset 0x10483 10832 bytes