Malicious PDF — malware analysis report

Static analysis result for SHA-256 9c388e4dd0fca050…

MALICIOUS

PDF

72.6 KB Created: 2021-07-01 22:27:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 82a7d46f4a4a1c0ae55d6de630ae61d4 SHA-1: 8cb688d7855838970dbcaab38404b25b3b242c74 SHA-256: 9c388e4dd0fca050224135a7eab049f2f9fde5e44165dc194c3bf742a5075aa6
156 Risk Score

Malware Insights

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

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites, likely to distribute further malware or phishing content. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a pattern of using disposable hosting for these links, suggesting an attempt to evade detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://propbrains.com/wp-content/plugins/super-forms/uploads/php/files/t9imq2l4ct3ib0ls5vq13iuos5/8757541765.pdf
    • http://phillipwhiting.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095c6ce882e7---7334398369.pdf
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d077867a61b---60335588099.pdf
    • http://iideree.org/wp-content/plugins/formcraft/file-upload/server/content/files/160bae5e316e49---sozivujefoteguketudunu.pdf
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160c908294affa---wotabirenus.pdf
    • http://retroldn.com/userfiles/file/kavixegaxujubaniv.pdf
    • http://grodgolf.com/clients/f/fd/fd83fa7079552abb47853a85229f74c1/File/28147968828.pdf
    • http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/7be4ck5qb76kpl8ildrb7ad22n/78916164663.pdf
    • http://techniq.ae/admin/uploadfiles/file/7690871353.pdf
    • http://portalcom-b2b.es/img/user///file/_0514502001621526495.pdf
    • http://alpha-th.com/userfiles/file/19002482482.pdf
    • http://africansafaris-spain.com/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/83086198792.pdf
    • https://plswa.com/wp-content/plugins/super-forms/uploads/php/files/829d338efb4635361889d2cb1cbb3fcb/10460614447.pdf
    • http://cancercareresearch.com/userfiles/file/39485223691.pdf
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a3f85190321---lazulugen.pdf
    • http://antoniolescio.net/userfiles/files/19208245922.pdf
    • https://borderpak.com/wp-content/plugins/super-forms/uploads/php/files/000e11a6a2a0674f1a31c38e2f440d14/pagasubefifilawanuxopuzi.pdf
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c2f3655820---fesifivuxiwogatiwade.pdf
    • https://tavio.ru/files/file/98317621954.pdf
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/dkhqrvf6mbefevk4kikj827iku/jatilowevilixid.pdf
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/daziworujulejidapilibobej.pdf
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/uep5mhbjdn1gn1q456n958bvga/bononozebik.pdf
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160908b4849ac0---9815190468.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=say+so+song+id
    • 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_off0000be17.bin
1745aa430e8ddbeeb656969590a8b4ceac8acc444793f1b26235799738e24dbf
pdf-font-stream PDF embedded font (sfnt) at offset 0xBE17 15668 bytes
font_01_sfnt_off0000e672.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE672 16792 bytes
font_02_sfnt_off0000fe89.bin
c45a19f6abaf2ddaf53baa6f2ec0b38d83036483ecb59c61d856cbb5033b1206
pdf-font-stream PDF embedded font (sfnt) at offset 0xFE89 10236 bytes