Malicious PDF — malware analysis report

Static analysis result for SHA-256 165500e503eed340…

MALICIOUS

PDF

81.4 KB Created: 2021-09-16 13:54:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 4fe65eb3a0289976377f776631bda71f SHA-1: b12d11cf35aeeb46770a38b4e9eaaca99563d521 SHA-256: 165500e503eed340ce8aaa4ca69e4cc2215419585fa3c04bf1ead1883df2bfe4
156 Risk Score

Malware Insights

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

The sample was detected as a malicious PDF by ClamAV and an ML classifier. It contains multiple embedded URLs pointing to compromised WordPress sites, which are likely used to host further malicious content or phishing pages. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for link farms, suggesting an attempt to obscure the true malicious infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/b0b126ed83a5c3555c7730e87fb4b752/defir.pdf In PDF document text
    • http://studio-rivetti.it/userfiles/files/41314129054.pdfIn PDF document text
    • https://leanuslab.com/UserFiles/file/74404164758.pdfIn PDF document text
    • https://szabolcsipeter.com/userfiles/file/6870282629.pdfIn PDF document text
    • http://www.ciesol.es/ckfinder/userfiles/files/14222448492.pdfIn PDF document text
    • https://fiberglasssupplydepot.com/userfiles/files/mewexi.pdfIn PDF document text
    • https://bselink.com/userfiles/file/tevelimolixameberesi.pdfIn PDF document text
    • http://mextro.de/upload/files/33483645418.pdfIn PDF document text
    • https://www.poolsrus.com.au/application/third_party/ckfinder/userfiles/files/41197227475.pdfIn PDF document text
    • http://www.commandinglife.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614236fe8ee71---54343485788.pdfIn PDF document text
    • http://minisadik-margaritka.ru/admin/ckfinder/userfiles/files/63798510339.pdfIn PDF document text
    • https://berettyobne.hu/userfiles/file/jidixima.pdfIn PDF document text
    • http://sunnysolutions.it/uploads/assets/file/fugovodigikibavumu.pdfIn PDF document text
    • https://fpcofmacon.com/nbloom/fckuploads/file/fulupujavanupezusewili.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135704e60845---mutapilatavofotojibob.pdfIn PDF document text
    • https://www.domaine-de-la-ferme.fr/ckfinder/userfiles/files/bivuroxij.pdfIn PDF document text
    • http://fqcycpa.com/jingkelun/userfiles/files/20210903115053.pdfIn PDF document text
    • https://eastoncn.housemember.com/uploads/files/muvivizukagifavipofone.pdfIn PDF document text
    • http://c2r.su/uploadfiles/file/2021091321573573499.pdfIn PDF document text
    • http://www.hermosabeachbungalows.com/userfiles/files/jawenazimuf.pdfIn PDF document text
    • http://zechnerbau.at/images/content/files/19352127565.pdfIn PDF document text
    • http://skupka23.ru/upload/m/widurerevatadelesivoxome.pdfIn PDF document text
    • https://axlthailand.com/imagexx/files/vewaroxofiwusiwifevisa.pdfIn PDF document text
    • http://oreoltour.ru/sites/default/files/file/zowebevinadig.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=enable+caller+id+on+androidPDF 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_off0000d93f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD93F 10220 bytes
SHA-256: 4ce3511ac0bf5db72c3aabfcf326a92da54acefaf5c8e4b498a7e341227e08d8
font_01_sfnt_off0000f02c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF02C 18296 bytes
SHA-256: 58812b0c41dcd41668ab6885b502e3f3019191a4866ca9849de969cddca38dd0
font_02_sfnt_off00011fbb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FBB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1