Malicious PDF — malware analysis report

Static analysis result for SHA-256 b548e2b9d1f89a97…

MALICIOUS

PDF

74.1 KB Created: 2021-09-06 13:47:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 166dfc8221c850694b59267d68cf1a02 SHA-1: 0acd8eb72325c50dc7171734b5b474f962a9bf23 SHA-256: b548e2b9d1f89a9745ddffff7553444f3a5c35c72cad1f418292bdbc46b64541
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm used for SEO manipulation or to distribute further malware. The presence of multiple external URIs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic strongly support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://relaxationplusmn.com/wp-content/plugins/super-forms/uploads/php/files/eec908cfc6c0d57ef5eb172075836ec9/mogor.pdf In PDF document text
    • https://ckmandarin.com/uploads/27897759182.pdfIn PDF document text
    • http://normel.org/files/upload/file/gekujonidudabepuz.pdfIn PDF document text
    • https://hensuyenpqa.traigiongthuha.com/ckfinder/userfiles/files/43764485690.pdfIn PDF document text
    • http://gerastar.com/userfiles/file/sapumidesavovarekeni.pdfIn PDF document text
    • http://www.cafeinca.com/img/public/contenido/file/kadewugunuxote.pdfIn PDF document text
    • http://tfforming.ru/d/files/99073281630.pdfIn PDF document text
    • https://hnhaa.com/userfiles/tnejp//files/75044128290.pdfIn PDF document text
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/a2d50e3ea02c522ab2ea5f9e745e0582/pudoriwokagomedebusubapak.pdfIn PDF document text
    • https://www.federatedlighting.com/wp-content/plugins/super-forms/uploads/php/files/5e0a9f7e947363cec8cf74e823d26ddd/pedekovatenaxeregidofipu.pdfIn PDF document text
    • http://jonme.net/ckupload/files/44510778446.pdfIn PDF document text
    • https://www.reachcast.ca/wp-content/plugins/super-forms/uploads/php/files/f4d7cd93edb2298fd2b3ac4b3cef1bd1/16058750005.pdfIn PDF document text
    • http://hrampetraipavlavosstanovlenie.ru/content/images/user/file/sabodo.pdfIn PDF document text
    • https://www.lightingdynamics.com/wp-content/plugins/super-forms/uploads/php/files/f582c78251895e38fe585922ef404844/jiwomunasobavasaruke.pdfIn PDF document text
    • https://www.hauptsache.cc/wp-content/plugins/formcraft/file-upload/server/content/files/16084c093de844---86878889174.pdfIn PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/0cf4984c4bd90dbc41dcf2dc46903a23/25083093559.pdfIn PDF document text
    • https://trsbarriersdirect.com/wp-content/plugins/super-forms/uploads/php/files/8k9t5gr0tuv534n5i5pe4eeliq/fejezaro.pdfIn PDF document text
    • https://thejasmineway.net/wp-content/plugins/super-forms/uploads/php/files/ivbai13758ulortqd17313oqca/dasamul.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608722d3549e1---51633400937.pdfIn PDF document text
    • http://wsmr.us/userfiles/file/49819341602.pdfIn PDF document text
    • http://angelojrobles.com/admin_initial_test/userfiles/file/negapesapu.pdfIn PDF document text
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/160b606b55141c---zenelariveleg.pdfIn PDF document text
    • https://fasaac.org/temp//files/25956645184.pdfIn PDF document text
    • http://nfc-lampang.com/user_img/files/meselixukutewaravobupe.pdfIn PDF document text
    • http://arci-mp.fr/admin/File/widuwiwinobiremud.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=international+commercial+law+books+pdfPDF 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_off0000bea4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBEA4 16580 bytes
SHA-256: 9ca85a20ebd612a742423f4f47c9032391276167ee66ab9a28e960db89e1f963
font_01_sfnt_off0000e95b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE95B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010172.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10172 11052 bytes
SHA-256: 74fbf010ef55d4e004439de3125dfea4f9c15f879764fa56af8ec4e780fa6108