Malicious PDF — malware analysis report

Static analysis result for SHA-256 5da8118363ed2a10…

MALICIOUS

PDF

94.0 KB Created: 2021-07-23 11:10:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: bcdc62a14f9a324938bb2ea27d58c66b SHA-1: 9f751ce0dbcf3633182c747bea4c06e31f53a270 SHA-256: 5da8118363ed2a10fb95fdcc5b32cfcdf8da508911f77412d3f0eae8bda644b5
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised WordPress sites acting as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The sample's structure and numerous links suggest an attempt to obscure the final malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://wilsonbarrera.com/inicio/wp-content/plugins/formcraft/file-upload/server/content/files/160bb50dcc1ded---84380993322.pdf
    • http://kqcme.yiaiwang.com.cn/upload/files/bevigapimepoduv.pdf
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/ruf3jo06n8jk9png40sh34o124/30021142165.pdf
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/2f5qn0l6tu1n46jhqbtqpbnasc/47095059421.pdf
    • https://ocw.tw/uploads/files/74689243410.pdf
    • https://www.eoluk.com/wp-content/plugins/super-forms/uploads/php/files/g177g53k2jgrlauvkt2ksdqhj2/xomovofitoni.pdf
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/gk157ag7cjgcpb033043704nh4/kafon.pdf
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096293bd242a---29536473607.pdf
    • https://satybharat.com/ci/userfiles/files/votinedagasifiwate.pdf
    • https://afanasyev-design.ru/wp-content/plugins/super-forms/uploads/php/files/7b70ec40356e17461a60285c2a1f4cde/vobuxivalepekozakal.pdf
    • http://kasaitogo.com/uploads/files/jenawuk.pdf
    • https://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/1607707f8100c9---93083582741.pdf
    • https://alixdemassy.fr/userfiles/file/faloligat.pdf
    • http://andreaslasnik.com/data/files/gapesab.pdf
    • https://mariapolis.net/ckfinder/userfiles/files/muzekinemubat.pdf
    • http://christopherspubandgrille.com/userfiles/files/59808011545.pdf
    • http://giovanninociti.com/userfiles/files/47924172009.pdf
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c876a23f3bd---8870568683.pdf
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16080f505e11f8---guruxatasesixukixefibakat.pdf
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/16090eb8ae0e99---39781805659.pdf
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cfe5fd569a9---jagoruxomi.pdf
    • https://fellowpeo.com/wp-content/plugins/super-forms/uploads/php/files/6700022923db67914fe14beb53dd9874/1077301658.pdf
    • https://soyana.de/js/ckfinder/userfiles/files/52614693641.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=interview+questions+and+answers+it+support
    • 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_off00010b19.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B19 16792 bytes
font_01_sfnt_off0001232b.bin
aa821a3da4a716954fca90f4dcc473d1404a030ac9ab9a5c2a2e3943b4418e6e
pdf-font-stream PDF embedded font (sfnt) at offset 0x1232B 17636 bytes
font_02_sfnt_off000151a1.bin
2b4924e998a2191ad2330e9ad7549fe73cbf87e4bc1e864ac15bfe594f71eace
pdf-font-stream PDF embedded font (sfnt) at offset 0x151A1 10688 bytes