Malicious PDF — malware analysis report

Static analysis result for SHA-256 1cb7b3583b54e571…

MALICIOUS

PDF

83.2 KB Created: 2021-09-04 00:28:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 40ade76fd45b0ad0c6f830911aec648e SHA-1: 28d79d226d5963e508c347a0e7864d6024e5880d SHA-256: 1cb7b3583b54e57187686cb6a6ff167479fa69a70bf24391a7d782f5886c9122
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised WordPress sites or disposable hosting, characteristic of a link farm used for phishing or malware distribution. The ClamAV detection and ML classifier strongly indicate malicious intent. The file's structure and embedded links suggest it's designed to lure users to malicious sites, likely as a spearphishing attachment.

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://laborke.ru/uplcv?utm_term=ap+sachivalayam+exam+paper+pdf
    • http://transchem-tech.com/Uploadfiles/files/wojokexelovimelowe.pdf
    • https://triptoboloyfoundation.org/editorsfiles/files/72964698147.pdf
    • http://yongqingtech.com/d/files/81239155161.pdf
    • https://tahitotfalu.hu/ckfinder/userfiles/files/rijunejonozitasebudusiwis.pdf
    • https://advance-pack.com/editor_upload/file/zufajofusilusabokus.pdf
    • https://sapsda.org/SapmaUserfiles/file/vinabeg.pdf
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a23b796c87a---95599134704.pdf
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/1612183af188bf---pitezewivagexixetogo.pdf
    • http://xn--80aamdqpfpr.xn--p1ai/upload_picture/powudikiwiginif.pdf
    • https://www.urban-quartz.co.uk/wp-content/plugins/super-forms/uploads/php/files/122cb2a6ad34889c6420430ef2c09820/kexufusovitopabib.pdf
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160951d77d7b09---76068488673.pdf
    • http://alemotta.com/resources/original/file/teluvazekemazimevemalit.pdf
    • https://ocvirapuato.com.mx/wp-content/plugins/super-forms/uploads/php/files/19a27b0ceb67ad99c248c2f769776e30/65571276254.pdf
    • http://aven.su/userfiles/file/85660887919.pdf
    • http://russkiivopros.com/images/FCKeditor/file/xijis.pdf
    • http://cyklo-sport-servis.cz/UserFiles/File/nurali.pdf
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/160867f9aeed7e---vakomexitamoduwoso.pdf
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb5736cf61b---vadufepopuwaju.pdf
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609878660462f---medipoledofinimageleb.pdf
    • http://apple888.vn/luutru/files/46139805199.pdf
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c5c7f481107---18168529062.pdf
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16092e1bdd9900---45974861475.pdf
    • http://aaaexpressac.com/userfiles/file/laradekazezedowewovekun.pdf
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/16071ed21bf1df---17953783982.pdf
    • 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_off0000e183.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE183 16792 bytes
font_01_sfnt_off0000f99a.bin
643f0160df6eee27d788c4b1df8716abee9e7f26432a2329f22c34affcabe228
pdf-font-stream PDF embedded font (sfnt) at offset 0xF99A 10828 bytes
font_02_sfnt_off0001129f.bin
5f630ce6f968d148612b4c41793f36a3456300376be1d6421b8868c80efa3903
pdf-font-stream PDF embedded font (sfnt) at offset 0x1129F 17212 bytes