Malicious PDF — malware analysis report

Static analysis result for SHA-256 f313ac15624596b4…

MALICIOUS

PDF

71.3 KB Created: 2021-09-27 02:02:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 7c430450da82a2b6049ad57c942790e2 SHA-1: 9b03380fa1b71c8a67b277eed8df10a5cd2ef9a3 SHA-256: f313ac15624596b419698a318c18bdb4ee493bea368cb55b9524369d7959f4d5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link farm with SEO-optimized keywords, suggesting an attempt to lure users to download software. Several heuristics indicate the PDF is designed as a link farm, with many distinct hosts and disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

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 http://fujieshubao.com/zk/UploadFile/file/2021092523134173499.pdf In PDF document text
    • https://tjp2-hotlink-j3t.com/contents/files/24425951012.pdfIn PDF document text
    • https://lorrainezammit.com/files/file/zalurigebapar.pdfIn PDF document text
    • https://shevtsov-art.com/uploads/files/karuweravugitopu.pdfIn PDF document text
    • http://nousgarage.com/userfiles/file/sosar.pdfIn PDF document text
    • http://thai-apsproducts.com/file_media/file_image/file/97155853522.pdfIn PDF document text
    • http://cageart.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1614b3122126b5---kanogexozegamuzinan.pdfIn PDF document text
    • https://adrfarysz.pl/userfiles/file/30242665478.pdfIn PDF document text
    • http://oilspecchem.com/files/senutub.pdfIn PDF document text
    • http://kenshopvn.com/uploads/files/woxitovisufemawuf.pdfIn PDF document text
    • https://detector-billetes.com/Imagenes/file/fazipa.pdfIn PDF document text
    • http://thegioichuyendong.info/app/webroot/upload/files/81184996183.pdfIn PDF document text
    • https://jpjplumbingandheating.com/FCKeditor/file/25535974277.pdfIn PDF document text
    • http://moscow-vernisage.com/files/files/58017421941.pdfIn PDF document text
    • http://jawarakreasi.com/file/derataberoxugowerimit.pdfIn PDF document text
    • http://archi-m.ru/userfiles/file/72016317893.pdfIn PDF document text
    • https://khmernative-rice.com/userfiles/file/38765534047.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614f288acb454---fifutawolojofilerore.pdfIn PDF document text
    • https://yumasri.com/assets/ckfinder/userfiles/files/wowedamalowixenet.pdfIn PDF document text
    • https://szabobuszrendeles.hu/files/files/gonored.pdfIn PDF document text
    • http://machin.kr/userData/board/file/70264395368.pdfIn PDF document text
    • http://studioguagnoni.it/userfiles/files/73299245923.pdfIn PDF document text
    • https://newsale.linyn.mobi/upload/ckeditor/pages/files/75389308148.pdfIn PDF document text
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137de96bda54---sekoximebadokivamelad.pdfIn PDF document text
    • https://lecachet.fr/docs/files/69291498196.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=need+for+speed+underground+2+download+for+pc+windows+7+32+bitPDF 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_off0000b16a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB16A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c97c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC97C 16128 bytes
SHA-256: 650c0196cd342d5d1b86cdef51d5c2a4fd525e379e939c559b2cba56e1b8e5b0
font_02_sfnt_off0000f1f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1F8 11440 bytes
SHA-256: 7ca04d304ad44fbe5b2a77bae350878f3cc4668d45170fa2190e097cbf3bffc9