Malicious PDF — malware analysis report

Static analysis result for SHA-256 85324b94bd6be535…

MALICIOUS

PDF

82.2 KB Created: 2021-09-03 20:31:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: bf871cefbc99ac8a0aae2f7dcc5dbb1b SHA-1: ec742e7771d97ed0ecf4f3bb46ebd0730aef5b06 SHA-256: 85324b94bd6be535ff5ae3e926d232d32f8d209bcf77c3e61ea94800aafeefa9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to multiple compromised websites, a common technique for distributing malware or conducting phishing attacks. The ML classifier and ClamAV detection strongly indicate malicious intent. Although no scripts were directly extracted, the PDF structure and embedded URLs suggest it's designed to redirect users to malicious content, likely as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://www.kowel.com/ckfinder/userfiles/files/1630673556.pdf
    • https://semineebrasov.ro/printuri-fi/files/63776554957.pdf
    • https://cungcapthitdetuoi.com/app/webroot/files/images/pages/files/61708869815.pdf
    • https://gamletaarnhuset.no/wp-content/plugins/formcraft/file-upload/server/content/files/1607da9463fbad---63434818278.pdf
    • http://hsiwww.com/image/files/20210804_174551.pdf
    • http://www.cheapmotorcycleinsurancepa.com/wp-content/plugins/super-forms/uploads/php/files/8qm0ungd5q8q9sotun9hh30504/mezamadujigofujof.pdf
    • https://travelone.ae/userfiles/files/wefaz.pdf
    • http://fst-uinsu.net/userfiles/files/jirum.pdf
    • https://tckontrola.hr/files/23583201467.pdf
    • http://poslovniimenik.net/firme_data/files/pomugegujopabasuwobo.pdf
    • http://generale-bureautique.fr/gdb/files/file/12735799815.pdf
    • http://yhbinternational.com/userfiles/file/37712213299.pdf
    • http://nutronicltd.com/userfiles/file/suwokowovuke.pdf
    • http://montpellier-businessplan.com/mbp/upload/images/images/upload/ckfinder/terujajedunuloxu.pdf
    • http://geyikkimya.com/userfiles/upload/file/26558963103.pdf
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/8d2d2377e4ff1bffcd13acee5a639714/mewuxotu.pdf
    • http://ags-sib.ru/ckfinder/userfiles/files/tadawojibanobufaluk.pdf
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/1607d234707593---besorijisedagazip.pdf
    • http://bukhatirhomes.com/userfiles/file/xaketife.pdf
    • http://castrolmintabolt.hu/images/upload/file/tifagitagixave.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ba7aea0900---9916337400.pdf
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac14ed17d44---49736996287.pdf
    • http://ngpsusa.com/wp-content/plugins/super-forms/uploads/php/files/m9bg6u91po7c2ieqsog16vdjet/34441779881.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=communication+system+pdf+manual
    • 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_off0000cc91.bin
b4b9f4c5c8a41db4161a8360fd40d6e2ced008a6d50461a5e8b09415a0bda2c5
pdf-font-stream PDF embedded font (sfnt) at offset 0xCC91 10928 bytes
font_01_sfnt_off0000e5eb.bin
6dd711d5324b005d9b1174d9c54e2231714ece27622d030c2f2444543147d81f
pdf-font-stream PDF embedded font (sfnt) at offset 0xE5EB 23792 bytes
font_02_sfnt_off0001238f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1238F 16792 bytes