Malicious PDF — malware analysis report

Static analysis result for SHA-256 b2bf834b720cc353…

MALICIOUS

PDF

84.0 KB Created: 2021-09-24 03:09:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: e494aad0f04714f9e823fe4e30175fac SHA-1: 98ac3b1c7e8f4f2b4b6a476c9e9e8ea69c49faaf SHA-256: b2bf834b720cc353f9e971dadf696d439445841333ae224224f55a19d4829d30
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as a phishing trojan and by an ML classifier with high confidence. It contains numerous embedded URLs, many of which point to compromised CMS upload storage or are part of a link farm on disposable hosting, suggesting an attempt to lure users to malicious sites. The presence of these links and the overall structure indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://www.feniuniversity.edu.bd/app/webroot/ckfinder/userfiles/files/44984833836.pdf In PDF document text
    • https://iwanbim.com/userfiles/files/2123325864.pdfIn PDF document text
    • https://arbormaster.net/uploads/files/67142371451.pdfIn PDF document text
    • http://123flower.doweb.kr/upload/files/41002289099.pdfIn PDF document text
    • http://minuspk.ru/minuspk.ru/userfiles/file/69695778733.pdfIn PDF document text
    • https://beruanglucu.com/contents/files/wisog.pdfIn PDF document text
    • https://www.harnoordesigns.com/wp-content/plugins/super-forms/uploads/php/files/f9e5fb94a928db3e16de694a006de5cf/xiketolalovefopiwedexune.pdfIn PDF document text
    • http://watchimport.eu/userfiles/file/65962685.pdfIn PDF document text
    • https://cobrawire.com/userfiles/files/40080549825.pdfIn PDF document text
    • http://feg.vn/uploads/files/11376259886.pdfIn PDF document text
    • http://maiodi.com/userfiles/files/jojuduzu.pdfIn PDF document text
    • http://w.scenekunstskolen-efteruddannelsen.dk/ckfinder/userfiles/files/pefojituxopoli.pdfIn PDF document text
    • http://hajnysport.cz/FCK_userfiles/file/puvufoxulonikudesid.pdfIn PDF document text
    • https://zhongzing.com/uploads/files/202109151202133688.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614cee4cc89a5---kelemamugazalogonotume.pdfIn PDF document text
    • https://groupunsur2.com/contents/files/zowewilevulakeva.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/1613358b04e978---vinazuvegam.pdfIn PDF document text
    • http://sga.cc/uploadfile/file///2021092023563859.pdfIn PDF document text
    • http://studio-rivetti.it/userfiles/files/73444178907.pdfIn PDF document text
    • https://nazragame.com/calisma2/files/uploads/wapifudisivum.pdfIn PDF document text
    • https://littleitalypizzany.com/nbloom/fckuploads/file/54674988551.pdfIn PDF document text
    • http://mweb.cz/images/file/34063377788.pdfIn PDF document text
    • http://slesnick.net/userfiles/files/kijezepemidi.pdfIn PDF document text
    • http://101eyewear.com/luutru/files/26697520272.pdfIn PDF document text
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612f38d962338---tuxuv.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=netboom+play+pc+games+on+mobile+apkPDF 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_off0000e151.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE151 10940 bytes
SHA-256: b1deea386914168411a28bb37c8dfb914615cc75ef9596b24b88fa6ab5004ba0
font_01_sfnt_off0000fa81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA81 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011293.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11293 17892 bytes
SHA-256: 02bc6cc2427522037690e92d3f83d7574dcfa28ce6ea61966ead9129c7124d0f