Malicious PDF — malware analysis report

Static analysis result for SHA-256 3815f4aaea1073e5…

MALICIOUS

PDF

81.7 KB Created: 2021-09-18 21:19:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c668cb439e36ed92c938546ecd57b2ac SHA-1: e2b5f7ec51fdfa63c90a5632551fba6b2f09ce8d SHA-256: 3815f4aaea1073e5ada0db10df15918f6eff2a0ce3a977f660f0e1ef5565479c
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as containing a link farm pointing to potentially compromised websites. The ML classifier and ClamAV also identified it as malicious. The document body is heavily obfuscated, but the presence of numerous external URIs, including one hosted on a compromised CMS upload directory, strongly suggests a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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
  • 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://krakow4you.pl/krakow/files/77402181083.pdf
    • http://restauraceeverest.cz/userfiles/file/fabosegovexemeretag.pdf
    • http://pmrs.ps/userfiles/file/rifitosefubegiwonorafiba.pdf
    • http://gediklimakinahidrolik.com/resimler/files/20551449179.pdf
    • http://kamakuralosgatos.com/uploads/files/xubusinonudupimikalifaza.pdf
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/ojd93oves51kn46gg0c4m91k07/zezosoxoxoxologaxiv.pdf
    • https://il-gusto.com/images/file/vuvidumupuwaxurokobobasap.pdf
    • http://artediapharma.com/upload/files/38204610130.pdf
    • http://sozopolihills.com/userfiles/file/40739344704.pdf
    • https://howardsteeves.com/wp-content/plugins/super-forms/uploads/php/files/2082a4eac826e40b738fb6f54f18fe31/rolegezukavop.pdf
    • http://kirakuramen.com/uploads/files/bobugeruvudulovasadonen.pdf
    • http://sb-78.ru/files/file/kejeze.pdf
    • https://ww150007.linebot.net/upfile/files/20210906153717.pdf
    • http://visit-pune.com/userfiles/file/53358601015.pdf
    • http://principessavencanice.com/wp-content/plugins/formcraft/file-upload/server/content/files/161421939b4e06---gigavuwozideg.pdf
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e20975e997---bizawezabitisasegegomikuz.pdf
    • http://ieeepes-thailand.org/app/webroot/files/files/fededinupa.pdf
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/da420fa6fec61875ee3a42805a81adc5/14438153167.pdf
    • http://abwlanham.com/uploads/files/limutagagefuxi.pdf
    • http://szjglaw.com/uploadfile/file/2021090614200673499.pdf
    • http://shrlie.com/upload_fck/file/2021-9-7/20210907043709111597.pdf
    • https://relleno-acidohialuronico.com/wp-content/plugins/super-forms/uploads/php/files/50be7d7059011484d60989ed5751fa2b/lipegorinesewonubu.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=ads+keep+on+popping+on+my+phone
    • 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_off0000db5a.bin
f96e174e12060d0bdb197d576b26d3fb16a38ead9fb5f00e36781d42852d748b
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB5A 10620 bytes
font_01_sfnt_off0000f334.bin
c711b9332481e53f74ecb83a7bdde51e3f3a6c478d8c81888709eda5acd95ed9
pdf-font-stream PDF embedded font (sfnt) at offset 0xF334 17616 bytes
font_02_sfnt_off000120d3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x120D3 16792 bytes