Malicious PDF — malware analysis report

Static analysis result for SHA-256 e850d8f2af0928be…

MALICIOUS

PDF

98.4 KB Created: 2021-08-05 12:57:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 339f266bf6ee6304d185de69a18c0dcf SHA-1: 3791dc53a29a000da7856ecf79c60bd5d264f6b3 SHA-256: e850d8f2af0928be56795f8b427542aa8c1c9bf5f3e2f276c20ba0e68c3361d5
204 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file is identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a phishing or trojan delivery mechanism. It contains a high number of external links, many pointing to compromised CMS upload directories, and includes a visual download button, suggesting an attempt to trick users into downloading further malicious content. The presence of embedded URLs and the overall structure indicate a spearphishing attachment attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 8

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://oncallanatomist.com/ckfinder/userfiles/files/gibifako.pdf In PDF document text
    • http://marthomaiticherukole.com/userfiles/file/59261278079.pdfIn PDF document text
    • https://swalaya.in/userfiles/file/44854734284.pdfIn PDF document text
    • http://ambulatorioveterinariopisillibertozzi.eu/userfiles/files/46061229495.pdfIn PDF document text
    • http://vigen12.com/userfiles/file/duxatedixebanuwemap.pdfIn PDF document text
    • http://tiwtactic.com/userfiles/files/pasobawalubiwosefavivijej.pdfIn PDF document text
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/627bc08af1ca83cc1529dd6c4220152d/18411714289.pdfIn PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607db9f220b1e---91749262037.pdfIn PDF document text
    • https://transcendenceit.com/wp-content/plugins/super-forms/uploads/php/files/74143bfd7ebb802b687feb48610750ae/kujavuxewijo.pdfIn PDF document text
    • http://chromavials.com/d/files/bavakotadiwuxopolowuz.pdfIn PDF document text
    • https://jerseyshorepirates.com/userfiles/files/61920422266.pdfIn PDF document text
    • http://gvs-russia.ru/admin/ckfinder/userfiles/files/gafisufivuxatu.pdfIn PDF document text
    • http://short-story.ru/upload/file/77785296182.pdfIn PDF document text
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16070fe16e1734---22137635305.pdfIn PDF document text
    • https://jackyrouxmethode.com/userfiles/file/35678213909.pdfIn PDF document text
    • https://12tiga.com/contents//files/44129700704.pdfIn PDF document text
    • https://xn--80aaaglcftt5alesfkk7f.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/8ce434ddd2869347b4d3fc2d0054c4f9/84895974751.pdfIn PDF document text
    • https://tranthachcaodanang.com/uploads/image/files/faxunetakiridijovosofiku.pdfIn PDF document text
    • https://makenie.com/upload/files/62966439619.pdfIn PDF document text
    • http://plnjl.com/userfiles/files/binopizubu.pdfIn PDF document text
    • https://cabsfromheathrow.com/userfiles/file/31668884826.pdfIn PDF document text
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070ee3426db1---73735248792.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=pubg+mobile+aim+assist+mod+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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010385.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10385 18068 bytes
SHA-256: 2e96466db08be6a5ef44be8fc5899ea6fdc9fd35b141d574e81f5ac6a0c67985
font_01_sfnt_off0001338f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1338F 10864 bytes
SHA-256: 979a54abf9109fbbe268633cb4af08af7d33432594534bdd1c23aff9d1d8479a
font_02_sfnt_off00014c47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14C47 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_03_sfnt_off00016458.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16458 16312 bytes
SHA-256: 7d15b2d6d265aaca51dda18faee70a1b8fa9d95ed54cb111fb0895789092f9ae