Malicious PDF — malware analysis report

Static analysis result for SHA-256 e62becf45d942a6b…

MALICIOUS

PDF

75.7 KB Created: 2021-09-23 13:33:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 3a7ac95031a2420c792a012604e963d7 SHA-1: 3482d42ab471c7ea21a0361173176bec9f12cf59 SHA-256: e62becf45d942a6b12111d78acb161bc4af00446430b1abfb5b066e2f3977d27
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which point to compromised CMS upload directories or disposable hosting. The ML classifier strongly indicated maliciousness, and the heuristic firings suggest this PDF is designed as a link farm to distribute traffic to potentially malicious sites. No scripts were extracted, but the structure and URL distribution are indicative of a malicious lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • 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://allytemp.ru/uplcv?utm_term=android+studio+screenshots PDF link annotation
    • http://manhchenang.vn/webroot/img/files/gofojizofived.pdfIn PDF document text
    • http://htbestcomputer.com/media/ftp/file/zemukaz.pdfIn PDF document text
    • http://pc580.cn/upload_fck/file/2021-9-3/20210903210027554842.pdfIn PDF document text
    • http://1utilaje.ro/mm/file/11314002684.pdfIn PDF document text
    • http://gzmzwl.com/Uploadfiles/files/57025551845.pdfIn PDF document text
    • http://www.vishalsahni.com/public/ckfinder/userfiles/files/tezufabop.pdfIn PDF document text
    • https://inchiriereelicopterromania.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16140607f45ad5---3420946156.pdfIn PDF document text
    • http://bociany.sk/media/file/getevogakaf.pdfIn PDF document text
    • http://hoangduy.vn/vn/files/87431918743.pdfIn PDF document text
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/161315611ca42f---4770532345.pdfIn PDF document text
    • http://atdawnwelift.com/userfiles/file/meselebi.pdfIn PDF document text
    • http://xn----9sbbnbtte4cyg.xn--p1ai/ckfinder/userfiles/files/33665016221.pdfIn PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/b0866d40c56752fa6408684e3f28e138/84044495816.pdfIn PDF document text
    • http://belean.pl/userfiles/file/74121612116.pdfIn PDF document text
    • https://mumegram.com/userfiles/file/56397389916.pdfIn PDF document text
    • http://lingvastar.z-i-g-z-a-g.com/userfiles/files/gurefavewativotopisi.pdfIn PDF document text
    • http://keyflounge.nl/userfiles/file/nobixovoxibaribuneteverud.pdfIn PDF document text
    • https://hotelpancharatna.com/assets/userfiles/files/3944622227.pdfIn PDF document text
    • http://iwort.de/userfiles/file/79305197152.pdfIn PDF document text
    • https://jdsliquorlocker.com/nbloom/fckuploads/file/45202342702.pdfIn PDF document text
    • https://n-zvuk.ru/upload/file/74346421029.pdfIn PDF document text
    • https://aljuboori.com/userfiles/files/43490875487.pdfIn PDF document text
    • https://glbtrader.com/userfiles/file/35581755614.pdfIn PDF document text
    • https://nyirfa.hu/uploads/files/bupevibaxonanebab.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_off0000c4bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4BB 10340 bytes
SHA-256: 4e0b37cd46cb3fba665de425559ed3794889457e9f430f46bb3458ef7067aaee
font_01_sfnt_off0000dc0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC0F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f421.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF421 17368 bytes
SHA-256: 313695ba4f8e24a0845c6ad042d04d490e547c55c4b32c7e827db837e9bab2f9