Malicious PDF — malware analysis report

Static analysis result for SHA-256 be51d1c853b34388…

MALICIOUS

PDF

88.8 KB Created: 2021-07-04 20:18:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e80f97c989e11161e1c793d24632e380 SHA-1: d63ae23c3817ccd143763e6dc78d9c0522035b09 SHA-256: be51d1c853b34388d00109b9f15672d23911f5e4b9bc8e733ca3a513c38f5fe3
204 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, with high-confidence heuristics indicating embedded JavaScript and links to external URLs. These links point to compromised WordPress sites and disposable hosting, suggesting an attempt to host malicious content or phishing pages. The presence of embedded JavaScript strongly suggests an attempt to execute code within the user's browser or PDF reader.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://coretry.ru/uplcv?utm_term=humans+existence+on+earth+timeline
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/1lbasqigcs3sh5o0i64vrpq4f7/16292821112.pdf
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606c915566186---dudisezesilemawu.pdf
    • https://www.marvistasales.com/wp-content/plugins/super-forms/uploads/php/files/1bda1e476853207fa5cfc23c42ebc0ff/13154875399.pdf
    • https://zegabilisim.com/calisma2/files/uploads/mavaviroxenajowar.pdf
    • https://alula.com/wp-content/plugins/super-forms/uploads/php/files/de4f6ef013f49a8aa0cdfa76ffe181f1/zazunakogofore.pdf
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/802eoibc9a0f9rff27b6243b13/6246837012.pdf
    • http://tantos.jp/js/upload/files/68269328775.pdf
    • http://thm-holding.ru/wp-content/plugins/super-forms/uploads/php/files/7d1316e6c09a5665b0434d4f6bb99a89/dobob.pdf
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c440ad766bb---bilefi.pdf
    • http://www.aluvascientific.com/UserFiles/file/29239187444.pdf
    • http://sakuragiramenandsushi.com/uploads/files/tekifibojazemibazifew.pdf
    • https://www.tangelo.no/wp-content/plugins/formcraft/file-upload/server/content/files/16071b80c8fcf4---98820936359.pdf
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160aa4d9466869---pikifovurubotubo.pdf
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1608b2d5e1caec---50692318132.pdf
    • http://bagandpack.ru/wp-content/plugins/super-forms/uploads/php/files/74c05d3266f255dcaca6fc51ed79a82d/zexibesovaxizojepu.pdf
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609effd6a81fd---domerede.pdf
    • http://kasintorn.com/images/upload/files/pobujozemurivas.pdf
    • http://eros-arena.de/eros/userfiles/file/32134652881.pdf
    • http://cageart.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160724a8825823---60332578.pdf
    • http://call.ae/wp-content/plugins/formcraft/file-upload/server/content/files/16080b9edeeebf---66345764679.pdf
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160aa360e913da---papot.pdf
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/u12ciqimstci3bm1b02v9rn21r/48927154838.pdf
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/f077b78038d22d3febb2ca358b4d81f3/xijobelujaburuvoxuruteb.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f81b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF81B 16792 bytes
font_01_sfnt_off00011032.bin
fdfb7a6d1af93e7aa7673c2b0f48cf59ec767682dcafd347d93c3b337741b70a
pdf-font-stream PDF embedded font (sfnt) at offset 0x11032 10688 bytes
font_02_sfnt_off00012876.bin
4267096124ed16fcc23e0defbe249c43fe07c6cd020a2dc0a3e886fe0b925609
pdf-font-stream PDF embedded font (sfnt) at offset 0x12876 17636 bytes