Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3ca88fcab944709…

MALICIOUS

PDF

76.3 KB Created: 2021-05-03 11:03:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: b7d1b3ad88d030d990f61f4603ca4e0d SHA-1: be43575b8f6d5907232f59595dc606d4cea0dde3 SHA-256: a3ca88fcab944709e4f4854a469ebff740836540afffda67c74b00b9b6953904
156 Risk Score

Malware Insights

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

The PDF contains numerous links, identified as a link farm, directing to compromised WordPress upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of multiple compromised CMS upload links suggests a coordinated effort to host malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://frontiersneurophotonics.org/wp-content/plugins/formcraft/file-upload/server/content/files/1/1608ce71f3ce74---75659473407.pdf
    • http://cageart.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16078e7100f986---6709673723.pdf
    • https://www.mnspineandsport.com/wp-content/plugins/super-forms/uploads/php/files/a3cf778d31673cb17f1a9e9bf20e8900/29398576901.pdf
    • https://afd.me.uk/wp-content/plugins/super-forms/uploads/php/files/a0as8fpmtck47kmm01g0ts04kn/54607986780.pdf
    • http://yuha.be/_files/file/kuxizunijegisiv.pdf
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/oir10n4dj47v6ivuk5c70q7tga/guxunafo.pdf
    • http://www.afamaresme.org/wp-content/plugins/formcraft/file-upload/server/content/files/16087fa71a9c8c---gumamemuraxev.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b468889da3---50046578640.pdf
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/160865e9681717---tugiziketigovovelagosisav.pdf
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607019e11f107---26559752603.pdf
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8cbd1f071---59918585846.pdf
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/185081b7bf322ab829b5fb50edd3ffc6/gekajorerarudivevok.pdf
    • http://israel-aliya.com/wp-content/plugins/super-forms/uploads/php/files/f6d0a795023701ee99ccb9a0665fa95f/dumomulufunilal.pdf
    • http://fortlauderdalelimorental.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608098867bdec---25569816593.pdf
    • http://akinmedikal.com/uploads/file/vupukesonikubad.pdf
    • https://www.analfissur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606efb443f802---puloxuzaxivejo.pdf
    • http://alarcon-v.com/editor_upload_image/file/27131635323.pdf
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073acd174733---27233991623.pdf
    • https://www.skyline-recruiting.com/wp-content/plugins/super-forms/uploads/php/files/5532a182ea32bc7f3f3191cf62c1941b/midujenidogezifadejamusuk.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=flaming+candle+wick+guide
    • 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://scripts.sil.org/OFL

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e2e3.bin
880860e48557ad9e3ab301141f654761f32f0ba052ef54f8ab1d1561288e361f
pdf-font-stream PDF embedded font (sfnt) at offset 0xE2E3 4788 bytes
font_01_sfnt_off0000f31b.bin
83173cc10fdae146bf6ca3397eea410378ff01ddf8739b5721fe3b156b9f5820
pdf-font-stream PDF embedded font (sfnt) at offset 0xF31B 10324 bytes
font_02_sfnt_off0001161d.bin
d1f4a20f0e35a0564be54678b929bb8c711862c507f070c2b9a6abea8daf4378
pdf-font-stream PDF embedded font (sfnt) at offset 0x1161D 4324 bytes