Malicious PDF — malware analysis report

Static analysis result for SHA-256 f50a6981137fb62c…

MALICIOUS

PDF

69.0 KB Created: 2021-09-28 00:30:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 69df9be8164696ea515dd5fa69fac7b0 SHA-1: e6a90bd0e760aac78bde65d4322e4c10cdbfbd57 SHA-256: f50a6981137fb62cdd0e85fa30fad76839543739fa92022eb5d095b296b21017
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF is identified as a phishing lure due to its image-only nature and small file size, typical of a screenshot designed to trick users. It contains numerous external URLs, including one pointing to 'laborke.ru', which is likely part of a redirection chain to a malicious site. The ClamAV detection and ML classifier further support its malicious classification.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

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
  • Image-only document with action trigger (screenshot lure) medium PDF_IMAGE_LURE
    PDF has 1 image(s), only 0 text block(s), carries a click-outward action, and is only 69 KB — typical shape of a phishing lure where a full-page screenshot hides a clickable button that launches or submits to an attacker URL.
  • 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://laborke.ru/uplcv?utm_term=all+videos+playing+in+slow+motion+android PDF link annotation
    • https://menu2uplus.com/images/file/20512261010.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613821db447a9---35188910431.pdfIn PDF document text
    • https://airflow-skateboards.com/userfiles/files/ruwikikudu.pdfIn PDF document text
    • https://pui-vital.ro/msg_media/file/nefuxubonane.pdfIn PDF document text
    • http://cjmfgx.morefriendship.com/upload/files/juforalamiserakatepusow.pdfIn PDF document text
    • http://hrampetraipavlavosstanovlenie.ru/content/images/user/file/vizizudoxelolemojuri.pdfIn PDF document text
    • http://showplus.ae/userfiles/files/72393077648.pdfIn PDF document text
    • https://ezokniga.com/uploads/file/sapupebuvumanofog.pdfIn PDF document text
    • https://hiroyoung.com/data/files/14385613902.pdfIn PDF document text
    • http://polesprogettazioni.com/userfiles/files/perarozafomaf.pdfIn PDF document text
    • http://nfrostov.ru/upload/files/mofetagatifumudonosovij.pdfIn PDF document text
    • http://shouce-image.kuchuancdn.com/Public/resource/files/7526396436.pdfIn PDF document text
    • http://minhquoc.vn/ckfinder/userfiles/files/boxafizoseturul.pdfIn PDF document text
    • https://jager-ig.tw/up_photo/file/kobidalowerir.pdfIn PDF document text
    • http://z-sinpro.com/upload/files/jidafejigafawelizaporar.pdfIn PDF document text
    • http://dgjinhak.kr/DATA/upload/files/202109241216542724.pdfIn PDF document text
    • https://seas2010.cienciaevida.pt/site/upload/file/vunuza.pdfIn PDF document text
    • https://biorenta.lt/ckfinder/userfiles/files/30808722327.pdfIn PDF document text
    • https://driftwoodcc.com/userfiles/files/ronajimunubixadobado.pdfIn PDF document text
    • https://granitabrasive.ro/editor_up/58608299964.pdfIn PDF document text
    • http://1carl.com/userfiles/file/wowonagofi.pdfIn PDF document text
    • http://dioceseofniranam.org/userfiles/file/38936866928.pdfIn PDF document text
    • http://identik.hu/editor_up/takanojomipo.pdfIn PDF document text
    • http://summitremodelinginc.com/userfiles/files/52370147584.pdfIn PDF document text
    • http://hzxf.com/images/upload/File/juwinimodafisurifiza.pdfIn PDF document text
    • 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_off0000af1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF1F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c731.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC731 14292 bytes
SHA-256: 111045a3cfbd5adefd02e4bb7d5493f555908e73b80fff5ddc5d74238619fed3
font_02_sfnt_off0000eadf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEADF 10980 bytes
SHA-256: 2e9d3ad6f12138fb31f08bdfcd2fe4449a4f1a1e51957f4a98822424052ddcb4