Malicious PDF — malware analysis report

Static analysis result for SHA-256 85a28193e30e812a…

MALICIOUS

PDF

78.1 KB Created: 2021-09-04 13:47:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: a6b103b44e0c5d7c7e219111e6eb17e2 SHA-1: cc22fb97163aef1dee3cc96e844dd2c6b3f8dd13 SHA-256: 85a28193e30e812a6fccbe6aa70eeecb51e054254cc90db1f4bfdf53e0bd8a76
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a link farm with numerous URLs pointing to other PDF files hosted on compromised CMS upload storage and disposable hosting. This suggests a phishing or malware distribution campaign, likely initiated via spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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://makenie.com/upload/files/mitituvaxovedibuduzozu.pdf In PDF document text
    • http://fcraregistration.com/UploadedData/file/3486441111.pdfIn PDF document text
    • http://classtool.info/upload/files/81263461457.pdfIn PDF document text
    • https://catequesisnavarra.org/guiarte_userfiles/files/lozotumumiduvepexu.pdfIn PDF document text
    • https://weeb.nu/userfiles/file/fiwafa.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb4ae2611c---pizurezudaxofa.pdfIn PDF document text
    • https://prolocolidodisavio.org/ckfinder/userfiles/files/mepadoforazel.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a919b57ef2a---sukaxipodut.pdfIn PDF document text
    • http://floral-design-lindgens.de/userfiles/file/ronolotadupasududejegaw.pdfIn PDF document text
    • https://www.sahabatkeluargahomecare.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a08c19a7dbc---14303304648.pdfIn PDF document text
    • https://catherinehourihan.art/wp-content/plugins/super-forms/uploads/php/files/a0899fb429b09a1a308a2717feab0723/dimofixe.pdfIn PDF document text
    • https://themodernla.com/wp-content/plugins/super-forms/uploads/php/files/7a2faad8f8b726131621221f269af57b/xejujinapobuzolo.pdfIn PDF document text
    • http://www.anglometais.com.br/adm/Editor/ckfinder/userfiles/files/35862867561.pdfIn PDF document text
    • https://kop-trans.pl/uploads/userfiles/files/kisusamogemabuno.pdfIn PDF document text
    • http://hongshengfish.com/uploadfiles/20210514/21051406020088974902fymwd5yp0a.pdfIn PDF document text
    • http://exclusivelimoservice.com/ckfinder/userfiles/files/pidumiwebidaberenekowi.pdfIn PDF document text
    • http://isleford.com/filespath/files/20210818195651.pdfIn PDF document text
    • http://footstepfloor.com/upfiles/files/dopeboporuzoludoz.pdfIn PDF document text
    • http://koreabulk.net/userData/board/file/96685101166.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/kunozososulera.pdfIn PDF document text
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/16123c36065eed---punanakenopiwigekobil.pdfIn PDF document text
    • https://mut-zur-veraenderung-hambuch.de/userfiles/file/88913834378.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/26971790304.pdfIn PDF document text
    • https://sellerflows.com/wp-content/plugins/super-forms/uploads/php/files/84548896cb7f227cd8ed5bb3ee8743d8/zigudivanafuz.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/24bipulov0dvi3q24slgj14hr5/9395806874.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c12340f030c---42455730445.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=conjunctions+worksheets+free+printablePDF 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_off0000ceb4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEB4 11156 bytes
SHA-256: b6e45f3939afea87384aa36fb6bf3745bbb138b34d7e02f92ff13768d61b48e9
font_01_sfnt_off0000e892.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE892 16448 bytes
SHA-256: 1c8c2f31550c079af14004b82d19893f4596ce2c3fd7771da921dac5bbb4e148
font_02_sfnt_off000112d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112D1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1