Malicious PDF — malware analysis report

Static analysis result for SHA-256 e528437f58f3dbff…

MALICIOUS

PDF

98.1 KB Created: 2021-07-05 14:42:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7a7fc3d92d9ddc1ddec167b75d6dec07 SHA-1: cf7cc4b6ec1a80ec6faf4b2e2696c20faf0215ab SHA-256: e528437f58f3dbff0db2de4ec0a7757de6c8d45844c8d96c349005b4692ebf13
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs pointing to various websites, many of which are hosted on compromised CMS platforms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is unreadable, but the heuristic firings and extensive URL list are sufficient to determine its function as a link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9872

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 https://archism.ru/uplcv?utm_term=definition+for+fastidious
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/c139fc6m9bf8bth1jehbq3t5ru/sufezuxivanitemubefosike.pdf
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/8ba91df6c6bc06f8b4a4052a74525a47/matumopovisawivi.pdf
    • http://omgmediatank.com/userfiles/files/93820372756.pdf
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085e0de8574a---faxikijedigoxase.pdf
    • https://pikhospital.com/ck_uploads/uploads/files/pelim.pdf
    • http://asbufestival.com/uploads/FCK_files/file/35073761471.pdf
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/31d4f38e7e29c25d071680d376241269/79593518005.pdf
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/pao8t8sdia3no27ch465rcff65/xufuxofibiviv.pdf
    • http://asbu.net/uploads/FCK_files/file/wutibuvop.pdf
    • http://jjburgerut.com/uploads/files/rojalawegumozibekaz.pdf
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/0bca664c2c8e491f662a3c1ac9365d1d/96891494704.pdf
    • http://www.rkcomdesignservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071cf400ffbe---34139291375.pdf
    • https://store-connector.com/_upload_bilder/_filemanager/file/52935796155.pdf
    • http://fatamorgana.fr/uploads/assets/file/miwejopa.pdf
    • https://aradmissions.com/ci/userfiles/files/rarapa.pdf
    • http://adams-gold.ru/archive/image/file/22904642001.pdf
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606d0094a7cdf---getemukamakos.pdf
    • https://web-sila.ru/wp-content/plugins/super-forms/uploads/php/files/6ec60af0c947adb4c7fddcc324691e16/24748471227.pdf
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608111ce09bec---64512335455.pdf
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/7e8516fa2432848cd9d9ed8e76103c24/81794292804.pdf
    • https://askopenko.com/wp-content/plugins/super-forms/uploads/php/files/4a7b438fecc5595437851a0a5bd8ae74/85679067635.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 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e95d.bin
463d63ae53d17b8e8fe5977029c97362700d30083bac5a12d52bbc63c713cea4
pdf-font-stream PDF embedded font (sfnt) at offset 0xE95D 16956 bytes
font_01_sfnt_off000101a6.bin
e3b9b823ceacd38f8e1065e136c7f5062cb50e847724c58d15d88decf9e7db67
pdf-font-stream PDF embedded font (sfnt) at offset 0x101A6 21524 bytes
font_02_sfnt_off000138d2.bin
0bcd6ee146fd2c025f090c8ef7fc6bc26f5f5c6611b07f40941054dcd27be6a7
pdf-font-stream PDF embedded font (sfnt) at offset 0x138D2 10404 bytes
font_03_sfnt_off0001507a.bin
3f974d9bff2d4a0e8040a411f419d67999033483ff4a59da5864e4dfbb65a1c0
pdf-font-stream PDF embedded font (sfnt) at offset 0x1507A 4252 bytes
font_04_sfnt_off00016030.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x16030 16792 bytes