Malicious PDF — malware analysis report

Static analysis result for SHA-256 25afa2b485cdaeb2…

MALICIOUS

PDF

81.0 KB Created: 2021-03-22 00:53:02 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 9bbec9dfb83805c7f5724f7983cd02fb SHA-1: 744e7c8452510aae98b7800c7c6b7c0f01eea796 SHA-256: 25afa2b485cdaeb2059318a8efea61c9ed87d6950cc7fa2f37a914c23f817a17
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a mass of external links, many of which are likely part of a link farm designed to improve SEO for malicious sites. The primary URL, https://vilenefex.ru/strik, is presented as a search result for a common technical problem, indicating a phishing or malware distribution lure. The ML classifier and ClamAV detection strongly support the malicious nature of this PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://vilenefex.ru/strik?utm_term=why+my+washing+machine+not+draining
    • https://cdn.sqhk.co/suzironanes/gfja9kZ/lokaratiwedaxibuki.pdf
    • https://vejevidumuruje.weebly.com/uploads/1/3/5/3/135302175/terimumaxo_razijevifires_kawinumu.pdf
    • https://lowijagaji.weebly.com/uploads/1/3/4/3/134394878/xegarogujix.pdf
    • https://deperomider.weebly.com/uploads/1/3/4/3/134344929/190e18c608.pdf
    • https://cdn.sqhk.co/rotonoba/hcwvhdU/49069119187.pdf
    • https://cdn.sqhk.co/bewewojiwo/KHVTieK/2265564686.pdf
    • https://gimexewevojux.weebly.com/uploads/1/3/4/5/134523505/timebakixajut_laxekew_bumimadovawej.pdf
    • https://gajodugibo.weebly.com/uploads/1/3/4/6/134635488/317a2b6aceb33a5.pdf
    • https://tawigijonepoter.weebly.com/uploads/1/3/4/0/134012415/zivetowugege.pdf
    • https://cdn.sqhk.co/bapisolel/fjbicih/nimamevefozifosukebugije.pdf
    • https://sonedolab.weebly.com/uploads/1/3/4/6/134630530/zuponuparajoguw-vosivakusab-gubimuvuko-donumotazi.pdf
    • https://federadedeladol.weebly.com/uploads/1/3/4/6/134626130/xigafajixaja.pdf
    • https://vebaxifi.weebly.com/uploads/1/3/4/3/134360040/lotakowogenag.pdf
    • http://kumululurug.scienceontheweb.net/50224992435.pdf
    • https://jizotigop.weebly.com/uploads/1/3/0/8/130874082/tigusepexov-xenom-famadabojipaf-fovimitegu.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://uploads.strikinglycdn.com/files/e1228f96-f9b4-464f-8597-3d8a16d021e0/bazipotopekesanetoxelu.pdf
    • https://uploads.strikinglycdn.com/files/5663d6c2-c61a-42be-bd62-69dd4481a341/wayne_dalton_garage_door_spring_cost.pdf
    • http://kavezusi.onlinewebshop.net/fufonemamelovovomumipu.pdf
    • http://pabewuvuxaf.onlinewebshop.net/tabla_de_conversion_de_centimetros_a_pies_y_pulgadas.pdf
    • https://uploads.strikinglycdn.com/files/fb760c96-cfad-4c0f-851f-0ad04630659e/ripap.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://scripts.sil.org/OFL

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f0ff.bin
3a85cdb5db08350dd552c4c3dc081e48374a7d2f279cbe287dca0fd38620290d
pdf-font-stream PDF embedded font (sfnt) at offset 0xF0FF 5316 bytes
font_01_sfnt_off000102fb.bin
75401faf59de6e15643958d3d6a52df2686bfd02a50b933363d498c10338f448
pdf-font-stream PDF embedded font (sfnt) at offset 0x102FB 11116 bytes
font_02_sfnt_off000128ac.bin
a542ec26cea93e049a2e27cd59b1347dd9bbdea13775fd7b822b3c2b3136116f
pdf-font-stream PDF embedded font (sfnt) at offset 0x128AC 4324 bytes