Malicious PDF — malware analysis report

Static analysis result for SHA-256 9c1c23807fd6bb7c…

MALICIOUS

PDF

79.8 KB Created: 2021-08-04 01:05:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3b56f0e57fb84cb970a72f7c3974bd3a SHA-1: 67d9a964f3883ea83be90625019830c87ea05950 SHA-256: 9c1c23807fd6bb7c728502238ce1452310b357432ef43c75c2ce6ef40f818abe
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for malicious PDFs to execute code. It also contains numerous external URIs, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

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://konferencii.ru/js/ckfinder/userfiles/files/wotap.pdf
    • https://krone-murten.ch/userfiles/files/3189888107.pdf
    • https://copab.tn/216mag.svn/uploads/files/80147783470.pdf
    • http://stasta.com/userfiles/file/wigataromedazuradugi.pdf
    • http://xn--80aaeiengkwpz6p.xn--p1ai/pub/file/53515530899.pdf
    • https://shotclock.ca/wp-content/plugins/super-forms/uploads/php/files/2226e514e0edf64d19bae1c37e4311a0/tosulaxatola.pdf
    • https://euroquimicadistribucion.com/zabaleta/data/imagenes_contenidos/file/gutewexonar.pdf
    • https://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/ed52abd9e29ff051cf14fa0e733889d8/79608431425.pdf
    • http://alarmy-kamery24.pl/userfiles/file/pumodudafuwewulosijetanej.pdf
    • https://yuss.it/file/6263055929.pdf
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607e37dd7fe74---50116189510.pdf
    • http://at2apigroup3.com/contents//files/momipufifu.pdf
    • http://laclonghotel.vn/upload/files/31386184444.pdf
    • http://primethailand.com/ckfinder/userfiles/files/17934500791.pdf
    • https://actorconseil.com/files/file/72845818506.pdf
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/160af85bedc7b4---xotetuwotavaxufubi.pdf
    • http://srihemkuntsahibfgp.org/hemkunt/userfiles/file/zigupuva.pdf
    • http://reklama-v-sochi.com/ckfinder/userfiles/files/kuteremoje.pdf
    • http://rszm88.com/upfolder/e/files/20210531002852.pdf
    • https://rosewoodcity.org/nbloom/fckuploads/file/zepisotibuj.pdf
    • https://elsa-daulte.com/ckfinder/userfiles/files/wegipigijafuba.pdf
    • https://protradingindia.net/userfiles/file/fasututugusogunor.pdf
    • http://peneleos.pl/userfiles/file/70880146720.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=how+to+reset+the+memory+on+a+one+touch+ultra+mini
    • 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_off0000d26b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD26B 16792 bytes
font_01_sfnt_off0000ea7d.bin
a53d7e9b2af7298c649dda2c61c296a2d6ee11f98e038a4349e4f510ba9a8d8b
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA7D 17324 bytes
font_02_sfnt_off0001179d.bin
1da87cf786a630322abcb2ddb753d45ce0161daa05aabfdd7cdb436d830bf1a0
pdf-font-stream PDF embedded font (sfnt) at offset 0x1179D 10788 bytes