Malicious PDF — malware analysis report

Static analysis result for SHA-256 a82fb899b56759bb…

MALICIOUS

PDF

154.7 KB Created: 2021-07-08 05:46:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: edfbb5cb1fe209a8419ab96dd5ced226 SHA-1: eafbe22dba9b60eac12f1c7218a4ded4e4034583 SHA-256: a82fb899b56759bb16208bb7b6c0910019f0b7fdb84eb8551f7cf971fbc12d17
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is identified as malicious by ML classifiers and ClamAV, indicating it's a phishing or trojan delivery mechanism. It functions as a link farm, directing users to multiple compromised WordPress upload directories and other disposable hosting sites. The presence of a 'Download button' heuristic suggests a lure to trick users into clicking malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9936

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://www.unicodesystems.com/wp-content/plugins/super-forms/uploads/php/files/c1ntvloikdcrr6f20s4tqvm053/69146468498.pdf
    • https://iominneapolis.com/wp-content/plugins/super-forms/uploads/php/files/a8514f237b6756a1fb37c58b271914b3/45176451957.pdf
    • https://brmc.jp/user_data/userfiles/files/debeminizutemikedununata.pdf
    • http://digemnd.com/UserFiles/file/goxaxonidogomop.pdf
    • https://www.idahomedia.com/wp-content/plugins/super-forms/uploads/php/files/05988674d34fc0d5648e37941547d815/38297224105.pdf
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/2b894b84b2b392b0e36a1e32b58f5d61/79203914629.pdf
    • http://al-bandak.com/userfiles/file/kiwuvina.pdf
    • https://mimpishio2bet.net/contents//files/48270023906.pdf
    • http://blissworldbeauty.com/newerac2c/userfiles/file/59131464256.pdf
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080dcdc38b93---6414714746.pdf
    • http://honda-vo.com/upload/file/73130540354.pdf
    • http://askort.pl/Upload/file/kovobazigijuvurifonirub.pdf
    • http://guides2alpes.fr/uploads/file/zelepaterawetaxubivovi.pdf
    • https://atraba-holding.com/userfiles/file/jitupewutumide.pdf
    • http://pierrevillers.fr/mairie_files/file/popilapasubezumefi.pdf
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/160e5b48d3d8ba---74590534528.pdf
    • https://ecohort.info/userfiles/files/4035424082.pdf
    • http://vudafrique.com/wp-content/plugins/super-forms/uploads/php/files/3ca4d498307e703d543d68c8bc7c4322/nowozojabufuparowo.pdf
    • http://dirabrealtors.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608dcc51e98d2---dikat.pdf
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160ddf19a56523---41164936982.pdf
    • https://alves.bg/ckfinder/userfiles/files/vawuwi.pdf
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a4dea435111---vuwetitibom.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=prince+philip+brother
    • 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_off0001f9e6.bin
b71746b03fc38aad416d6f1dad83f39d03f1ed5d21afcdf481cb06b435dd7426
pdf-font-stream PDF embedded font (sfnt) at offset 0x1F9E6 20208 bytes
font_01_sfnt_off00022cde.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x22CDE 16792 bytes
font_02_sfnt_off000244f5.bin
18d2525794af2028921c9516b60efb275a5c816da0fbdf089fc695eb1622c788
pdf-font-stream PDF embedded font (sfnt) at offset 0x244F5 10284 bytes