Malicious PDF — malware analysis report

Static analysis result for SHA-256 a27ecbe4dbb11155…

MALICIOUS

PDF

76.5 KB Created: 2021-07-02 22:57:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 54691025f2ebf2ea4c6e97f016755612 SHA-1: 3854343129ec4f08355c70b3cae0b9025089874d SHA-256: a27ecbe4dbb11155bef72bdc3cabc3c8124c379d4bd2116c88ff3109728be012
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to compromised CMS uploads and disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The presence of external URIs and the overall structure strongly indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://medprobr.com.br/wp-content/plugins/super-forms/uploads/php/files/8df1796be1d88c4c00f1107d9bdb7dd8/jevujenidefisojadadav.pdf
    • http://lamelove-zakryti.cz/userfiles/file/leponu.pdf
    • http://heritagecarletonplace.com/clients/c/c2/c23aa4fb54f25340752d20cfcff880b2/File/kefeje.pdf
    • https://www.officinadelgustoroma.com/wp-content/plugins/super-forms/uploads/php/files/a396c91ca068d66da15e77a41be5ee9b/11470423899.pdf
    • https://nevisnews.com/userfiles/77442109616.pdf
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/afcd4be10dc60e94fbb4eb59d7c9624e/mubuwinuniviges.pdf
    • https://topupdana.com/contents//files/padonoji.pdf
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8e697a838---kosudikokiwizojepozurof.pdf
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160d5c7f037ebf---58678997747.pdf
    • https://chaplains-camps.org/upload_picture/file/buseni.pdf
    • http://bjsprt.com/uploadfile/file///2021062904443763.pdf
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160810696aaa49---91679156462.pdf
    • http://lorichphoto.com/pictures/file/fonati.pdf
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160801ddd08f0d---20847685082.pdf
    • http://www.associatedomains.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072941fc2be7---87495850770.pdf
    • http://jhferry.com/data/fckeditor/file///bogexalagijifiberivikimep.pdf
    • http://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/7166f4fc4fb7e6bbc2bd8f873512f53c/letamikewurakofivusego.pdf
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087b73dc50c2---zegikobizivifi.pdf
    • https://www.entornopublicitario.com/wp-content/plugins/super-forms/uploads/php/files/418f1ddb77b1aaaf2b02047295d7b8f8/puxebipatidageguridutuw.pdf
    • https://bellevuecommunityfoodbank.org/wp-content/plugins/super-forms/uploads/php/files/fce35ef84f55f311c0a9c80922c70533/28501158560.pdf
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/698af4cde120930e94bb0eaef76cf5b6/92825998953.pdf
    • http://studiostocchi.eu/userfiles/files/59529894351.pdf
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/160dccb497a60b---sajimuloxeteropo.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=wiley+plus+accounting+answers+chapter+1
    • 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_off0000c8a5.bin
bb5e01d5336c3684856740c10962374a2c788ec48530a4d3b15303c0fea11169
pdf-font-stream PDF embedded font (sfnt) at offset 0xC8A5 11000 bytes
font_01_sfnt_off0000e24a.bin
da1c57decf3c9c62998ed656b2fdec900cb88a2f9e6120d55dd363e93dfc0750
pdf-font-stream PDF embedded font (sfnt) at offset 0xE24A 16340 bytes
font_02_sfnt_off00010cbe.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10CBE 16792 bytes