Malicious PDF — malware analysis report

Static analysis result for SHA-256 23b9b93ad0420ef8…

MALICIOUS

PDF

83.7 KB Created: 2021-07-01 16:47:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6541ba15c7a05458d879da76d6926f9b SHA-1: 6df1333b611563875829f22200c8401ff184412d SHA-256: 23b9b93ad0420ef8c9c6603ff2129fb4dc4673827cd68cae2f4b2126db9610d0
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs pointing to compromised WordPress sites and other domains, suggesting it functions as a link farm. These links likely lead to phishing pages or further malware downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://oniceh.ru/uplcv?utm_term=immigration+in+tamil
    • https://apparel.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/268793ca36cb13b4df259a1db863b42c/67744367145.pdf
    • http://cl-pub.com/files/files/30597941391.pdf
    • http://stardentalcare.org/userfiles/file/75454448377.pdf
    • https://sportcity.bg/webroot/img/content/files/dodas.pdf
    • http://el-system.jp/uploads/2012/files/35129575355.pdf
    • https://www.sahabatkeluargahomecare.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8bd3119f2f---72253501283.pdf
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/160cc5eed3af19---gefiwonugepimufogivubi.pdf
    • https://phoenixknights.co.uk/wp-content/plugins/super-forms/uploads/php/files/d9c31a33bca83e95b119a386862b37ba/xobop.pdf
    • http://stphilomenaonline.org/userfiles/file/3853657444.pdf
    • http://stjconsulting.it/userfiles/files/renujavuvalelapotuxopuvu.pdf
    • https://www.harnoordesigns.com/wp-content/plugins/super-forms/uploads/php/files/ku4sprp01kvhaqi1f94bd18up5/25899684910.pdf
    • https://djennebeads.com/nbloom/fckuploads/file/mataxak.pdf
    • https://boldvision.tv/wp-content/plugins/formcraft/file-upload/server/content/files/160da2cc9c0d51---50340146137.pdf
    • http://nedirajtebosnu.net/userfiles/file/97057960363.pdf
    • https://binarbaidequipment.com/public_html/userfiles/file/tabifenozux.pdf
    • http://fobosgrunt.ru/files/ckfinder/files/jatir.pdf
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c53d2e02fe1---23580398087.pdf
    • https://jpjplumbingandheating.com/FCKeditor/file/7251265520.pdf
    • https://kfz-gutachter-oliver-schiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ba6cede9f3f---20951447010.pdf
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/16070367f28315---futuxewimuxoxidizanef.pdf
    • https://eandjfamilyhealthcenter.com/wp-content/plugins/super-forms/uploads/php/files/eebfd9011fa5e471f4a28ada3b49be21/dabodunibuluz.pdf
    • https://arerp.kr/data/file///11838429166.pdf
    • http://www.niziointerior.pl/upload/file/43327859120.pdf
    • 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_off0000e65d.bin
245c5e9d5d175796468d7c7fbcc458755904175cd7a51a98367e4b11b44f8951
pdf-font-stream PDF embedded font (sfnt) at offset 0xE65D 16632 bytes
font_01_sfnt_off0001119c.bin
cdca6a1b824ba1ba8fc906a3a20a6b059a19d657daa6e0a5c63598baaf936a13
pdf-font-stream PDF embedded font (sfnt) at offset 0x1119C 10104 bytes
font_02_sfnt_off00012808.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12808 16792 bytes