Malicious PDF — malware analysis report

Static analysis result for SHA-256 41770a750218b334…

MALICIOUS

PDF

82.4 KB Created: 2021-09-17 03:52:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 56aebafe335af6c2e74b8d1fd40d41c4 SHA-1: 42b831ade4968de47e7b0aea7fd9bdaf7bd4b608 SHA-256: 41770a750218b3349883f154b366297ade7e81adf0a56573d9c6f8801af671d9
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The presence of external URIs and a link farm heuristic indicates an attempt to direct users away from the current document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9780

Heuristics 6

  • 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 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://majedalkarkhi.com/pics/file/28999973949.pdf In PDF document text
    • https://gangnampools.com/contents/files/66477447031.pdfIn PDF document text
    • http://rayanchem.com/d/files/29703077342.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/2a3k6olts0hvanpoks6ik27677/80285933774.pdfIn PDF document text
    • https://mimpiindah168.com/contents/files/98021714828.pdfIn PDF document text
    • http://vincitydata.com/uploads/ckfinder/files/87776755192.pdfIn PDF document text
    • http://mmprogetti.it/userfiles/files/tafelefujixifejufiki.pdfIn PDF document text
    • http://mingmitrcoffee.com/user_img/files/fogebutegagebasumunutejos.pdfIn PDF document text
    • https://phukienbep.net/media/files/1487005544.pdfIn PDF document text
    • https://melnikhouse.com/userfiles/file/21207361957.pdfIn PDF document text
    • http://cesarrodarte.com/userfiles/file/60735329433.pdfIn PDF document text
    • http://reklamaopole.pl/userfiles/file/19188031929.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/16133d2366d5dd---milavetarejajaj.pdfIn PDF document text
    • http://vuonlan.vn/data/upload/files/tupufosabe.pdfIn PDF document text
    • http://gyarmatilovastorna.hu/userfiles/file/93682069211.pdfIn PDF document text
    • http://yuqiaohome.com/uploads/files/202109021808174916.pdfIn PDF document text
    • http://king-tableware.com/uploads/files/202109032126301602.pdfIn PDF document text
    • http://e5tbr.alruaa.com/ckeditor-ckfinder-integration/uploads/files/47946877312.pdfIn PDF document text
    • https://completecollegestrategies.com/wp-content/plugins/super-forms/uploads/php/files/869b3b82235d4265741b85b023863310/molat.pdfIn PDF document text
    • http://2018.letnifestiwal.pl/ckfinder/userfiles/files/39525820268.pdfIn PDF document text
    • https://szpital-sulecin.pl/images/fckfiles/file/68878679535.pdfIn PDF document text
    • http://philipp-haberland.de/images/upload/file/befugikupijeromewowimo.pdfIn PDF document text
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bab23745c6---kugesibufaxaradevineli.pdfIn PDF document text
    • http://cecev.com/stockages/files/91067483465.pdfIn PDF document text
    • http://exima.kr/userData/board/file/69372859166.pdfIn PDF document text
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132d83567cee---lulizesen.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=age+of+empires+game+for+androidPDF 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_off0000c8cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8CD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e0df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0DF 22576 bytes
SHA-256: 8c98a4977f261150fa55d9a2638eb1bf3d72c6e590eefb1954259796a8915334
font_02_sfnt_off000119f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119F0 10676 bytes
SHA-256: d13656768aaedb2114f468a296120af53de2d19d0b482d48c91a2109e0b024d3
font_03_sfnt_off0001321e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1321E 1924 bytes
SHA-256: b3c88c1e19850007cfb8aeb5473549a66b9fc136d23d75e8b3bd398b023e3081